Sanderxpander

For the rest, as cparmerlee also said, it all depends. I think your system may be capable enough for your needs. Of course you can run into limits (mainly HD speed) but a 3rd gen i7 (even a mobile one) and 8GB of RAM is really quite good. Upgrading your laptop with a new internal HD is kind of a hassle with reinstalling the OS and everything, but even if you're not against getting a new system, why not start by getting that soundcard and a nice big monitor and get to work? Installing Sonar itself won't take that long and you can easily move all your projects (and use the monitor and soundcard) if you do need a bigger/better system.

And i7 w/ GB RAM is way beyond the Q9300 w/ GB RAM that i'm running.   A fast external drive to run projects may not be a bad idea either if it's practical.
 

Sanderxpander
Upgrading your laptop with a new internal HD is kind of a hassle with reinstalling the OS and everything,

Some of the companies specializing in selling laptop HD upgrades also sell a hardware/software kit that makes it very easy to clone your current hard drive onto the new hard drive.  Basically you use USB to connect the new drive outside of the notebook case.  Once you have copied everything, you power off and swap the drives.  If there is a faster HD that is compatible with your notebook, it is really a rather simple operation, and doesn't require a new OS install.  I think those upgrade kits cost about $30 (not counting the new hard drive), but can be used over and over, for example, to periodically copy your entire hard drive for backup.
 
OTOH, I'm not sure that the hard drive speed would really make a big difference.  I'd definitely try it with the current HD and just see how busy the drive is on the projects you do.

There are laptops with dual monitor support.  Dell Alienware 14 gaming laptop for instance.  There are many out there.
 
so looking at specs of your current laptop you can add a 2nd monitor and use the laptop screen and extend the windows screen to the added extra monitor.  your laptop has integrated video.
 
a laptop with a integrated onboard video sometimes shares the main computer memory.  this can take cpu speed and memory away from other things like SONAR.  a laptop that has a video card dedicated to processing video takes this load off the cpu and has it's own dedicated memory freeing up this process.
 
this goes the same for desktop computers.
 
integrated video - not so great.  takes cpu and memory away from program use.
single dedicated video - better.  frees up cpu to work on other things and frees up main memory to work on other things.
dual dedicated video - way better.  each monitor gets a video card to handle that graphic and it's own memory.
 
win7 or win8 with sonar?  well sonar is now optimized to use win8 but works perfectly good in win7.
 
I bought a new computer that came with windows 8 on it.  I could not stand using windows 8.  it's different and there is a lot to learn.  I did not want to spend my time learning how Microsoft wants me to use my computer.  I returned the computer and bought a different computer that had windows 7 pro installed on it.  This was simply a matter of my investment of time use and familiarity.
 
my experience started with a laptop and a simple cheap sound interface.  I had a small screen so I added a 2nd monitor old school CRT monitor which was easer on my eyes but it took space. then I added a separate keyboard and mouse for better typing and ease of using a mouse.  my desk space started growing and cables and whatnot was getting crowded. the hard speed was 5400 and I was getting drop outs in audio playback and very high latency with the interface.  I just wasn't happy using this configuration.  I was always fighting desk space and the computer and not being creative - getting to the music.  Then the laptop died. bought a new laptop that was a bit better newer tech and it was a bit easier to use but 2nd laptop dies in time.
 
Then I went desktop computer but I didn't have the money at the time to get everything I wanted so started adding and upgrading the computer.  still fighting the computer limitations.
 
so I now over time I have learned more and more what technology is best when using sonar and audio production recording and what my needs are to feel comfortable playing and using sonar.
 
My current configuration is all about comfort, speed and convenience for me.  fast computer, lots of memory, big monitors freed up clean work space. I have invested a LOT of money and time in my configuration.
 
The reason I am writing all this is for you to consider what your needs are, what is going to make you comfortable having fun being creative and making music.
 
with what you have currently throw a 2nd monitor on your laptop, get sonar X2/X3, buy a good decent sound interface and start using your setup and you will discover what your path is.  the 2nd monitor and interface can be used later on in a different configuration be it a different laptop or a desktop in the future.  it's not a wasted investment.
 
Hope that is helpful.

I am sorry- my ADD took over- I could not focus that long to make it through initial post in all details. From what I understand- you asking if Sonar is good for individual musician and if it is a good idea to use lap top to run it.
 
I am solo musician, using Sonar only to record my project. It meeds my needs.
 
I use LapTop for occasional live performances- it will run it ok, but I would use Desktop.
 
Building computers is easy. Took me 3 days of research and 2 days to order parts and build it. I do not recommend to use any "Studio Cats" to build your computer as he had difficult schedule (no contact after 9 pm, no weekends, which I respect but this is when I do everything), and was charging about 1/3 more than if you did it yourself. I built my Music Custom PC Ivy Bridge in January, and another Custom PC in Haswell in July. Now I am working on building CustoMac. You can consult on www.tomsharware.com it is a forum for builders, or post here in computer building section (and send me PM if you like) I would look at your list and make recommendations.

There is a lot of nice feedback here.
 
My situation is very similar to the OP in that I do music for "fun" and often get this sinking feeling that if it were not fun, I would stop.
 
For me, I use a laptop (for other programs), but find them very restrictive. For my studio, I wanted to have the ability to "turn it on, and record" and can do so in under 2 minutes flat. My external audio interface is an M-Audio Ozone (which thankfully has 64-bit drivers), and when I ask about a new device similar to folks, I get the response "An audio interface and MIDI controller in the same device? I do not know of such a thing..." I will be crying my eyes out if this ever dies.
 
Having kids, I was always dealing with taking 30 minutes to set up, and could not leave cables plugged in, which no longer exists... so can have a "dedicated work area."
 
Desktops have more "upgradability," run cooler, and allow more to be added to them (i.e. made more "powerful" than a desktop). I think with SONAR, being able to "see" is important. I built my machine for Win7 64-bit use, and backed out of a Win8 upgrade when I saw that Win8 cannot be "uninstalled." Now I am reading posts that Win8 drivers will not work in Win8.1, which has me even more committed to Win7.
 
For me, I can simply turn on the external audio, sound system it feeds, switch to the extended desktop (if desired), plug in something (if other than MIDI or the mic) and go. This has always been the place I wanted to be, but was not "there" until 2 years ago.
 
The "Sandy bridge" machines like mine are "obsolete" now, but I saw info which still benchmarked mine at #10, so it is still very powerful (the graphics card and SSD would be overkill for many users though). These can still be built very cheaply by custom vendors, and are worth researching... bottom line (for me) was the time to get up and running, performance, and being able to see my GUI's without issues. The a-g items in the original post would be "N/A" with a desktop imho.
 
Michael

If I ever get another desk, I'll go dual monitor. I had such a setup before, and I can tell you it's time-saver and sight-saver. I did this under Sony Vegas for video/audio editing. With Sonar, I'd throw the Console view up one monitor, and Track view on the other.
 

If you're going to be loading large samples I feel an SSD is a must.
 
Loading an SD3 drumkit on my i5/7200rpm laptop takes forever.  It's painful.
 
The same kit will load from my desktop SSD in a couple of seconds.
 
Loading projects is a lot worse/better.
 

I have an 18.3" laptop display with a Matrox Dual Head 2 Go device attached to the VGA and USB ports that allows you to connect 2 displays to you laptop. That gives me 3 screens if I want.

Desktop and dual monitor (for the time being).  Desktops are cool since you can switch the easy parts - hds, memory, slot stuff.  Your dual monitoring will be a slotted - that is the cheapest way.  Matrox is better but twice as much.  And no need to use the usb drive, just slap a second hd inside.
 
The safest and best way is to get one of the music computer builders here to make you one.  Alas, I've never had the money for one of those here at home, but have had great sucess w/ SONY and HP the last 12 years.  Yea, the OEM software is full of crap and bloat, but otherwise they use pretty good components.  As a bonus, all my kids got a desktop as I upgraded.  Once you do the kind of tweaking that Studio Cats etc. do you have a good music computer.
 
Two monitors are good.  My best setup was 2 large matched CTRs.  Right now I have a large flatscreen for the timeline and a smaller one w/ the browser and dock.  I'm waiting for prices to fall to get a same large-sized touchscreen to place below the non-touch so they line up.  I'm hoping this Christmas prices will fall far enough so I can pick one up as a present to myself.  That would be the optimum I think.
 
@

vladasyn...post here in computer building section (and send me PM if you like) I would look at your list and make recommendations.

 
I've posted in Gear / Computers / $3,000 Plus Build Sonar X2/X3 Producer Advice Please.
 
Anyone who has the expertise to chime in is more than welcome to advise me as to the exact hardware pieces that would work best so I hope to see at least some of you there.  You've all been such a great help and I am honored to be a contributor here.  FYI I've decided not to use my Asus laptop as a DAW.