Quote - A couple of things.
The 7900 GS is a decent graphics card, but definitely not the fastest on the block. Consider a 7950 GT - somewhat more expensive, but much, much better for gaming.
OpenGL drivers - this is nVidia. Which means good OpenGL support and good XP64 / Wista support.
The onboard sound system of the mainboard is already 7.1. Unless you're an audio freak, it is good enough. You can save some serious bucks by not adding the sound card.
Swap the Western DIgital drives for Seagate Barracuda 7200.10 drives. Those are faster and more silent.

I'd recommend looking into an Intel Core 2 Duo system based on an E6400 CPU. The price should be comparable to what you've posted here, and as of this summer, the Intels deliver more processing power per dollar.

Thanks svdl! 

Will see if I can afford a 7950GT, and I will definitely stick with nVidia.  And you saved me $80 on the sound card!

I did scope out one Intel alternative which substituted the following for the AMD chip and mobo:

Intel Core 2 Duo E6600 Conroe 2.4GHz 4M shared L2 Cache LGA 775
plus
ASUS P5N32-E SLI Plus LGA 775 NVIDIA nForce 650i SLI ATX Intel Motherboard

Compared to the AMD rig of--
AMD Athlon 64 X2 5200+ Windsor 2.6GHz 2 x 1MB L2 Cache Socket AM2
plus
ASUS M2N-E SLI Socket AM2 NVIDIA nForce 500 SLI MCP ATX AMD Motherboard

... it was about $220 more expensive on newegg for the Intel setup, though I may well have some apples and oranges issues there, perhaps especially with the the motherboard...?

So I need to explore more I guess, though studies show that having too many choices makes consumers LESS happy... "options overload" or something like that.

cheers...