AMD 8350 is a better value compared to the i7 3770.  You could use the $100+ difference on RAM, software or a higher end board.  If you are into video editing the 8 cores are nice.

I have the AMD 8350 and I love it. Rock solid, no issues. 

My first suggestion would be to possibly consider freezing down the synths and only having those synths that you are using, unfrozen. This would probably help a great deal. Also limit the amount of plugins for eq and such that you use until the very final stages of mixing, this way you concentrate more on talouring your sounds to the frequency range, rather than having to go back in and eq the crap out of them, using more time and cpu power in the process.

I would also suggest reading up on disabling services that run in windows in the background, stealing valuable cpu cycles. Also things like speedstep/C1E/C-States which may benefit you if you disable them. This will bring your base system resource usage to a bare minimum, so that your audio progs can utilise as much as possible without out any hiccups. But please as said, read up on it all, including your mobo/bios manual, cross reference with experiences online. You'll find this alone will boost your available power and reduce any glitchiness.
Oh, and make sure you back up before any changes and then also write down every thing you do, so you can trace your steps backwards if you start to notice issues.

I am currently in the process of rebuilding my daw and using tools like DPClat and Latmon, Windows ADK xperf, I am all ready getting my system down to 26 active processes at base start up, which is around 15 less than a standard un-modified windows install. I've still got loads to disable including networking (still updating everything, drivers for all chipsets and updates for programs downloaded) so this will drop a few more. It frees up ram, cpu cycles, reduces pagefaults, ISR's and dpc spikes which will all help in their own way.

I overclock my Phenom II 965 and I have no issues.  However I'm sure Sonar does not benefit in any real way from my 0.4GHz overclock.  If you're running out of CPU horsepower with the amount of plugins you have, in my opinion, no amount of overclocking for your CPU will help, realistically.  You might get one or two more plugins working but you run the risk of instability.  In my opinion, if your CPU can't handle what you're throwing at it, then you should freeze tracks as suggested or maybe consider a complete system upgrade. 
 
I have no stability issues with my CPU overclocked, but its overclocked so I can play games on my computer.  There are a number of tricks as outlined above to increase your computers ability to handle what your doing with Sonar.  I'd try those first.
 
I upgraded to an FX-6350 and I had no change in Sonar.  That's because what I do in Sonar doesn't stress it at all.  When I upgrade again I'll buy the fastest CPU I can get for about $200 - whatever that may be.  Sonar for me works with my 2008-era AMD CPU and I have no plans on stressing Sonar beyond that.  I upgrade for games.  I play games on my Sonar machine because I use Sonar in cycles for personal music - I don't professionally "produce" anything.  If I was to be more of a professional music producer I would go Mac or a separate DAW computer that I don't overclock.
 
As I'm sure you're aware, you cannot "upgrade" from an AMD to an Intel without changing the motherboard.  You need to figure that into your cost.  I considered upgrading from my Phenom to an Intel but I'd have to get a new CPU (obviously) plus a new motherboard with it's associated costs.  Instead I spent $139 on a new CPU and I got a tangible benefit in my games. 
 
As far as AMD vs. Intel, it's 6 of one, half dozen of another.  I've always used AMD.  If I wanted the ABSOLUTELY FASTEST COMPUTER at any cost, Intel is the only way to go.  Period.  However, I have never built a computer with cost being irrelevant.  So that is why I choose AMD.  If you are going to produce professional music and must have the fastest computer possible, and Intel I7 is probably your best bet. 
 
For me, I just compare an AMD Fx 8 series ($150) CPU upgrade to an Intel I7 upgrade ($300 CPU plus motherboard) - it's no question the AMD CPU is cheaper.  But it's clear in all computer literature, that the Intel series CPUs are faster in almost all cases.  So that is your decision to make.
 
You have to figure if an Intel CPU upgrade will even work on your motherboard - if not you'll have to upgrade the motherboard (and possibly the RAM) as well.  In my case I bought a new CPU.  In your case that might not be such an easy task. 

I OC'd my just slightly.
I too have an OC-ing option built in but did loads of reading and tweaked mine manually. Much more stable that way.
Not needed but I just wanted to play since it was my first build.
 
Mike