Hi - I am new to the Mac world but I know a PC with those specs would probably struggle under the requirements of CS3 Master Suite. Most of the Adobe software is pretty resource hungry. I would imagine that you could install it but I dont know that it would run well enough for it to be worth your time.
Again I am totally new to macs so it is very likely that I am wrong =0
I'm running Adobe CS3 on a G4 500MHz tower machine right now. It gets the job done. It's by no means "speedy," but it works and is responsive enough for day-to-day work.