What’s the NIC for? Doesn’t that board have two already built in?
Ditch the IDE hard drive and go with SATA. Personally, I would use the included raid and go with a pair of SATA drives.
I would also go with a 7800 video card. Despite what other peeps have said, it is worth the price. It has noticeably better performance and runs a lot cooler/quieter than the 6800’s
Also, while the DC AMD chip is a good pick, you should get some better cooling for it. The best air cooling is still a Swifty pin sink with a Delta. You can quiet it down by going with a 120mm fan and an adapter.
As for sound, I would use the onboard for now, and wait a few months. There are some new cards on the horizon that should push the state of the art.
EDIT:
You also don't neet that $250 board unless you plan to SLI a pair of vid cards. One of the sub $100 boards will do you fine. We actually don't use the ASUS boards for HiPo systems. The DFI Lanparty boards are the top of the line at the moment.
This is what I would use
Lanparty 
Re: OT: New PC!
Threaded Mode