Well about the hardware part here is my advise :
CPU : Intel Core 2 Duo E6600 2.4Ghrz
MO/BO : DFI Infinity 975 G/X
RAM : Supertalent 2GB kit (2x1GB) timings (5-5-5-15) 1000Mhrz
SVGA : GeCube ATi Radeon X1900XT 512MB
HDD Raptor-X 10.000 RPM 74GB (Primary)
Why GeCube SVGA?
Cause is relativly cheaper and it performs the same as other brands.