Okay, from my research for my build roughly the same price range this is what I would say to get (these are estimates)
4000+ or 3800+ dual core CPU------$330
7800GTX----------------------------------$460
DFI Lanparty Ultra-D-------------------$130
Creative SB X-Fi-------------------------$120
Antec TruepowerII 550 watts--------$90
2GB OCZ Platinum RAM----------------$250
Seagate Barracuda 250GB----------- $100
DVD-ROM or DVD Burner---------------$20 (Player) or $40 (Burner)
Case---------------------------------------$60+
Nice Speakers/Headphones----------$40+
Total = $1600+ depending on what case, speakers/headphones, hard drive, and optical drive you get and assuming you have your own monitor.