Build the PC for gaming, If you can choose hardware that also lets you mess around with OSX86 on it bonus, but don't count on the current bootleg of OSX working over the long term, I'd advise againsed building an entire system just to run a hacked OS. It may prove to be incompatible with whatever they finally come out with.
PB G4 15" 1.2ghz - Pismo G3 400 mhz - iBook G3 500 "Jukebox"
"SawSmurf" G4 500 - Quicksilver G4 Dual 1ghz modding...