brconflict

Sycraft
I recommend against all-in-ones since they use proprietary hardware and thus are difficult to repair or upgrade, and often cost more. Also monitors tend to outlive computers quite a bit and with an AIO you are tying a monitor to computer hardware so you can have to toss a perfectly good monitor just because the computer has gotten too old to be usable.
 
However, if you wish to have a Windows AIO then Dell is probably the way to go. An Optiplex 7440 would be a good choice, or an XPS 27 touch.

I agree with this as well. Get a basic machine from Directron.com or someplace like that, buy the basic machine but leave open options to expand, change, etc. I bought a box with extra slots for video card/audio card upgrade potential as time moved on. Never know when you might need four 30" screens and 3 or 4 sound-cards down the road as they become cheaper, but Sonar grows bigger.

 
Whilst I  agree that a tower PC is clearly the best choice with regard to upgradabilty and flexibility, the repairability is only partially true. I have an all in one that I bought to use as a server for our media room. They have  more  user repairabilty than a laptop. You obviosly can't change the motherboard easily,  but as with a laptop, the 'consumables' like hdd's, power supplies and ram are user changeable. Even the wreless elements are just usb components that are installed internally.
 
The main disadvantage of an all in one for use as a daw is that unlike a laptop, there is no way to natively run a second monitor. If that doesn't bother you, and as the OP stated you like the look and convenience, there are plenty of options that will run Sonar for many years. With modern PC's you don't necessarily always have to sacrifice style for utility:)

tenfoot

brconflict

Sycraft
I recommend against all-in-ones since they use proprietary hardware and thus are difficult to repair or upgrade, and often cost more. Also monitors tend to outlive computers quite a bit and with an AIO you are tying a monitor to computer hardware so you can have to toss a perfectly good monitor just because the computer has gotten too old to be usable.
 
However, if you wish to have a Windows AIO then Dell is probably the way to go. An Optiplex 7440 would be a good choice, or an XPS 27 touch.

I agree with this as well. Get a basic machine from Directron.com or someplace like that, buy the basic machine but leave open options to expand, change, etc. I bought a box with extra slots for video card/audio card upgrade potential as time moved on. Never know when you might need four 30" screens and 3 or 4 sound-cards down the road as they become cheaper, but Sonar grows bigger.

 
Whilst I  agree that a tower PC is clearly the best choice with regard to upgradabilty and flexibility, the repairability is only partially true. I have an all in one that I bought to use as a server for our media room. They have  more  user repairabilty than a laptop. You obviosly can't change the motherboard easily,  but as with a laptop, the 'consumables' like hdd's, power supplies and ram are user changeable. Even the wreless elements are just usb components that are installed internally.
 
The main disadvantage of an all in one for use as a daw is that unlike a laptop, there is no way to natively run a second monitor. If that doesn't bother you, and as the OP stated you like the look and convenience, there are plenty of options that will run Sonar for many years. With modern PC's you don't necessarily always have to sacrifice style for utility:)

Personally, I find the tower PC to be the easiest to service/upgrade, and definitely the most flexible.

brconflict
Personally, I find the tower PC to be the easiest to service/upgrade, and definitely the most flexible.

For sure Brian -  as I said I agree that it is the most flexible and easiest to service, but the alternatives are not as impossibly inaccessible as they were in the past. 

tenfoot
For sure Brian -  as I said I agree that it is the most flexible and easiest to service, but the alternatives are not as impossibly inaccessible as they were in the past. 

Have you serviced/upgraded a recent build iMac?
It can certainly be done... but it's not for the faint-of-heart.
You have to pull off the display (cutting the adhesive around the entire perimeter).
This and especially re-attaching (with appropriate adhesive strips) are the toughest tasks.
If you want to swap out the CPU, you literally have to take apart the entire unit.
 
Other all-in-one solutions are likely not this tedious...
But it's a major pain compared to a rack, tower, or even custom laptop.

Jim Roseberry

tenfoot
For sure Brian -  as I said I agree that it is the most flexible and easiest to service, but the alternatives are not as impossibly inaccessible as they were in the past. 

Have you serviced/upgraded a recent build iMac?
It can certainly be done... but it's not for the faint-of-heart.
You have to pull off the display (cutting the adhesive around the entire perimeter).
This and especially re-attaching (with appropriate adhesive strips) are the toughest tasks.
If you want to swap out the CPU, you literally have to take apart the entire unit.
 
Other all-in-one solutions are likely not this tedious...
But it's a major pain compared to a rack, tower, or even custom laptop.

 
I was referring to the HP All in one that I referenced in the earlier post Jim, and am really only talking about end user service issues like replacing a hdd or upgrading ram.  I haven't serviced any Macs for a couple of years now,  but they were always a nightmare to work on. 

Upgrading a CPU is a nice thought but at the rate Intel drops new socket standards to the market it's hardly ever worth the money and effort. RAM and disks is about it and with Thunderbolt and USB3, arguably even disks aren't that important anymore to have internally. And PCI-e based stuff of course but even that is mostly high end graphics cards for gamers and 3d rendering. 
 
Don't get me wrong, I have a tower case and I've reused it, and my screens. Definitely better value than an entirely new system. But "upgrading" these days basically means swapping out mobo/CPU/RAM etc for a newer set. 

Sanderxpander
 
Don't get me wrong, I have a tower case and I've reused it, and my screens. Definitely better value than an entirely new system. But "upgrading" these days basically means swapping out mobo/CPU/RAM etc for a newer set. 

I tend to think along these same lines as well, pretty much everything but the above can be carried forward and (re-)used, then as peripherals eat it, upgrade those with forward compatibility. My PCIe 2.0 GPU conked out last year, so I upgraded to a 3.0 that works in a 2.0 slot... one day when my MB gives up its ghost, the GPU can be scavenged for the new machine.

Sanderxpander
Upgrading a CPU is a nice thought but at the rate Intel drops new socket standards to the market it's hardly ever worth the money and effort. RAM and disks is about it and with Thunderbolt and USB3, arguably even disks aren't that important anymore to have internally. And PCI-e based stuff of course but even that is mostly high end graphics cards for gamers and 3d rendering. 
 
Don't get me wrong, I have a tower case and I've reused it, and my screens. Definitely better value than an entirely new system. But "upgrading" these days basically means swapping out mobo/CPU/RAM etc for a newer set. 

Totally agree Sanderexpander. 

Jim Roseberry
Have you serviced/upgraded a recent build iMac?
It can certainly be done... but it's not for the faint-of-heart.

Ya for the most part I tell people to treat Macs as disposable. So long as you have Apple Care, which you can have for a maximum of 3 years, Apple will fix it via whatever means necessary including replacing the computer. However after that, if it breaks you need to be ready to throw it out. It CAN be serviced, but it is often not worth it, and some thigns are just impossible to fix due to lack of parts and access.

One other point I should re-state in a new way is that tower-type machines can be built with maximum power and utility. As your needs grow, assuming your Mother-board/CPU combo was good to begin with, pretty much all other aspects of the system can be freshened up a bit with little expense and trouble. The point, however, is that most all-in-one machines, laptops, mini-desktops, etc. are typically a degradation of maximum potential, so that they can use less power, lessen heat-generation, and noise.
 
I agree field-serviceable components are worthwhile upgrades, but upgrades to speed the embedded services up might be too much to take. In other words, once the OS or drivers are no longer supported in the box, you are forced to upgrade, and can't typically piecemeal those components. Towers allow you to upgrade the power supply, mother-board/CPU combo, add/remove slots, expend USB, PCI-e, SATA, etc. options as you see fit. And parts are cheaper, too.
 
EDIT: Overall point of this thread is how Sonar would perform on a Mac through Parallels. Apple no longer REALLY provides a tower, and the options they do provide are best suited to new hardware, or very powerful older hardware. Regardless, when attempting to run a program designed to run natively close to hardware, it is imperative to afford the maximum amount of resources to that program. To emulate the OS and run Sonar on an emulated machines, is likely to take a back-seat to the MAC OS X. To run it on a smaller form-factor machine where performance is degraded intentionally to cut down on heat/energy consumption is likely to be even worse. The best scenario for a case like Sonar is to run it on the most reasonable hardware available, regardless of size. It must perform and be cost-effective.