I know Vegas 8.1 didn't work very well with Windows 7 64-bit and I assume one can no longer purchase Vegas 9 so has anyone used Windows 7 32-bit with Vegas 8 or 9?
I don't want any of the newer versions of Vegas that are GPU dependent.
The new versions are not GPU dependent. They can use a GPU but they do not have to. I don't use it. One computer is running Win 7 64 bit with Vegas Pro 12 and the other is windows 10 with Vegas Pro 12. Both are Core 2 duo computers with 4gig memory. Slow to render, but rock solid and are happy not using GPUs.
There is no reason for anyone to every use a 32-bit operating system again. Don't do it.
Vegas Pro 8.0c will work perfectly fine with Windows 7 64-bit. You don't need a 32-bit OS to run 32-bit programs. You will be doing your self such a disservice by limiting your OS to 32-bits that it's not worth it.
You can use Windows 7 64-bit with any software that runs on Windows 32-bit to 64-bit including Vegas Pro 8.0c. Why limit yourself?