does he want 1 PCI-E 16x slot or 2?
I would suggest the DFI NF4 Lanparty motherboard
2x512MB G.Skill RAM
Nvidia 6800 GT PCI-E (be careful not to get the AGP version if you get a PCI-E motherboard)
sound card: use the onboard sound of the motherboard, there is really not much difference between it and an Audigy
LG 4163B 16X Dual Layer DVD burner
case: anything you like, but if you get a cheap case with a PSU, do not use the PSU. one thing that's important is the power your computer gets. if you have a cheap PSU, it will often fluctuate, not deliver enough power, deliver too much, or fail completely.
I would suggest a PSU from Thermaltake, Antec or Enermax
Seagate or Western Digital 200GB Hard Drive - Seagate and Western digital make good quality hard drives