You can upgrade to Artist for $29 right now.. 
All versions going back to 7 have the options of 32 or 64 during install. 
 
 

Actually all versions going back to Sonar 5 have the choice as that's when x64 Sonar was introduced. They it's been 10 years since Cakewalk went to 64 bit.

So if I had a 2 GHz computer with 4 GIG RAM and I don't use a whole lot of softsynths, would there be a performance advantage if I installed the 32 bit instead of the 64 bit or does the bitrate have to match between the program and the operating system?
I'm thinking that maybe installing the 32 bit Sonar the computer wouldn't be working as hard as with the 64 and be faster as a result. But I'm not sure if that is really the case.
I'm not a high end pro so I don't need that ultimate sound quality,easy workflow and simplicity are my main concern. I'm just interested in upgrading because i am starting to find programs that I would like to try that won't even install on XP.

Roxy
So does the bitrate have to match between the program and the operating system?

Not quite.  If you have a 64-bit operating system, you can choose to install 32-bit SONAR or 64-bit SONAR or both.
 
If you have a 32-bit operating system, you have only one choice, to install 32-bit SONAR.
 

I would be looking at 64 bit windows, 64 bit Sonar with 8gb minimum as an upgrade. Even for an amateur. Otherwise why bother upgrading. Easy workflow and simplicity is everybodies priority.

Avoid 32 bit as much as possible if you value performance and stability.

OK, I know what to do now with Sonar. Thanks for your help.
I have other programs I'm hoping they will work under win 7 64 bit. We'll see.

Roxy
So if I had a 2 GHz computer with 4 GIG RAM and I don't use a whole lot of softsynths, would there be a performance advantage if I installed the 32 bit instead of the 64 bit or does the bitrate have to match between the program and the operating system?
I'm thinking that maybe installing the 32 bit Sonar the computer wouldn't be working as hard as with the 64 and be faster as a result. But I'm not sure if that is really the case.

 
It is possible that there might be a minimal performance advantage to going 64 bit Windows and Sonar, but the tradeoff is that you will have less available system memory on a 64 bit system with only 4 Gig. The 64 bit systems give each process access to more memory, but the system itself takes more memory to operate--eating into your total 4 Gig. So unless you have a single program that will be using more than 2 GB (or between 2-3 if you use special switches), you will not get any extra space for that program. Microsoft recommends 2 GB just to run Win 7 x 64 as opposed to 1 Gig for x32, so unless you are running more than 4 GB installed the advantage is with 32 bits in most cases.
 

The computer I'm looking at is from a refurbisher and I think I might be able to get him to put in a couple of extra goodies. What about  Win 7 vs Win 8 ? He's got a couple of Win 8 machines too for not that much more money.Would Sonar 8 still work on one of those?

Roxy
...if I installed the 32 bit instead of the 64 bit...

 
I would install both and judge for yourself.

This is the full picture. Not just size of memory but the way it is allocated. Other advantages as well. I would dump 32 as soon as you can.


http://lifehacker.com/5431284/the-lifehacker-guide-to-64-bit-vs-32-bit-operating-systems

Drivers work better imho.
Not only that 32 bit support is slowly being dumped. 32 bit drivers esp.