Really what you are doing is working in a very slow environment. I still have 2 computers running XP and they are just sooooo sloooowww compaired to a W8.1 with a SSD drive. I can go make coffee while my XP laptop boots up and settles down.
W8.1 SSD is like less than 40 seconds and Sonar is ready to go. Every action is instant. Rendering audio is super fast. You really notice this when using Wave Lab. 
If you have time on your hands then more power to you, but I get little enouh time for music and I don't wish to waste it while Sonar takes 3 minutes to export a song. 
Computers are very reasonable in cost compaired to other audio equipment. And the new versions of Sonar are just way ahead of 8.5 now. I still have 8.5 on my XP laptop, I loved 8.5 ( 6 is no comparison)  so I'm not just trying to sell you on Platinum or Professional. But the speed and workflow is just way way better if you deside to step up to the plate.  
You can use your registered copy of 8.5 to upgrade at a very resonable price. For me it was $99 for X3 Studio, then another $99 for Professional and now $149 to go all the way to the flagship of Sonar all nice and new and up to date. 
If you register your copy they will soon send you offers.  
 
 

You can always upgrade. Load up Sonar 8 and start having some fun!!
 
Rocky

I have a new presonus 22vsl audio interface because my old tascam US 428 was not working properly anymore.
So when I installed Sonar 8 and I couldn't get the midi to work I was thinking it was either the new interface or the Sonar 8 software. I have Band In A Box and that was not working either so I blamed it on Presonus. I called Presonus and they absolutely stonewalled me because I still use XP. The are really a terrible company, I have never encountered "customer service" that was less helpful. So  when i could not get any help from them I reinstalled my Tascam and that's when I figured out that the problem all along was my Ketron SD2 midi module. It is made in Italy and it really sounded great but not nomore. It's dead.I guess the Italians are good at making stuff that is really cool but not always dependable. Oh Well...
So now I have my old trusty Edirol SD 80 Studio Canvas hooked up and everything works. It just doesn't sound quite as good.
Currently I have Sonar 6.2 and Sonar 8.3 installed on my laptop. I don't know if there is a way to uninstall Sonar 6 now. 6 and 8 are both in the Cakewalk folder. The 6 folder is much larger with may more files than Sonar 8. So I'm afraid that I would get rid of stuff that I might want if I uninstalled Sonar 6 now.
I have a 500 GIG drive on my laptop so I'm not hurting for storage. I guess there's no harm in keeping both programs installed.
But I'm committed to learning how to use Sonar 8 and I'm going to order that Sonar Power book for it.

If, as you say, disc space is  not a concern, then I recommend you leave 6.2 installed as well as 8.

The learning curve is very, very steep.
I have recorded live bands for years, landed in a workflow comfort zone, and am now beginning to introduce drum synths and bass guitar plugs - and the learning curve begins again. Sonar is so, so deep. Even the older versions.
 
FWIW, I have 8.5 installed on an  32-bit Atom-based laptop which I use to record bands at their practice rooms (2x Tascam interfaces, US-1641 and US-1800) and record 28 tracks simultaneously with no hitches.
For mixdown and mastering I move the tracks to a Win7 64x machine with Sonar X3e.

YOu should really dig into what you can do with soft synths. Those sound modules you mention can  both  be out done by the TTS-1 which is built in and so easy to use. 
There are many free VST's from sites like KVR. 
And as I said for $30 you could get an upgrade from 6 or 8.5. to Artist. If you like it then there will always be more upgrades offered down the road as you see fit. 
http://www.sweetwater.com/store/detail/SonarArtUpAS
 
You keep all your old version installed and Artist will use the VST's that came with those too. 
If your using a cracked version then I understand your reluctance to purchase. 

I don't know much about this plugin stuff yet. I have the  sound modules because I was thinking that a soft synth would bog down my computer too much. Which is also why i bought the AudioBox 22VSLinterface . It has onboard effects that I can use for monitoring and I can also record with those effects. Probably good for people who still use older computers with XP. Too bad that Presonus absolutely refuses to even talk to XP users.
But I'm starting too look at maybe getting a used Thinkpad with Windows 7. They are much cheaper than I had thought. But first I'm going to see what I can do with my current setup.

The effects are actually in the driver, not in the box. But they are fine for confidence reverb.

Oh well, I was under the impression that the effects are in the box and that that will free up resources on the computer. I guess I was wrong. Still nice to be able to record without having it totally dry

Given your situation, 8 is the answer... It's a great DAW, great version.
Too bad 8.5 was a paid update from 8.... Some great features got introduced in that version.