I have 64 Bit Vista and FPS Creator x10 works like a charm.
I don't have the other program you mentioned, but I have a bunch of other programs which work great
many 32 bit programs work, but many programs have a 64 bit version.
And those which are high rated programs such as the one you mentioned.
I would choose a 64 bit instead of 32 bit as 64 bit is much more powerful than 32 bit and will allow you to have 8 GB of ram.
The more the better
Make sure you have a Direct X10 computer, or FPS Creator wont work at all.
Aero Files offers you high quality assets in the FPS Creatore store. Go there now.