For motherboard, processor and gfx card
DFI Lanparty Nforce 4 (Ultra or SLI, depending if you want SLI for the future)
AMD 3200+ whinchester, and a 3500+ if you have leftpver money
Geforce 6800GT, PCI-E. Evga is a good brand.
Oh yeah, buy the gear at newegg.com