Wait, its a pain in the butt to find driver compatable with x64, theres only one game that i know of that actully supports X64 (farcry). And from what ive seen in a few benchmarks, if you play 32 bit games in the 64 bit OS it actually plays slower.
just by an x64 system just windows xp 32bit edition. thats all, the only problem going to 64 bit now is hard to find drivers and not much campatbility yeat.