If you're asking which one is better, the 7900 is by far more superior.Hmm... an 8600? 7900?
COOLER MASTER Centurion 5 CAC-T05-WW Black/Silver Aluminum Bezel, SECC Chassis ATX Mid Tower Computer Case - Retail - $49.99
GIGABYTE GA-P35-DS3L LGA 775 Intel P35 ATX Intel Motherboard - Retail - $94.99
EVGA 320-P2-N811-AR GeForce 8800GTS 320MB 320-bit GDDR3 PCI Express x16 HDCP Ready SLI Supported Video Card - Retail - $289.99
Intel Core 2 Duo E6600 Conroe 2.4GHz LGA 775 Processor Model BX80557E6600 - Retail - $227.00
CORSAIR XMS2 2GB (2 x 1GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X2048-6400C4 - Retail - $107.00
Western Digital Caviar SE16 WD2500KS 250GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM - $67.99
SAMSUNG 20X DVD±R DVD Burner Black SATA Model SH-203B - OEM - $34.99
Corsair 520 from buy.com $89.99
Subtotal: $961.94
MIR: -$20.00 Video Card
MIR: -$10.00 Case
MIR: -$40.00 RAM
TOTAL : $891.94
If you can buy with a q6600 for that cheap and the rest of the set-up is built with decent parts then maybe thats the way to go... if not here's a possible build
GTS - Better then GT, but not quite the bestLE - Budget and lowest type
GS - Better but not the best
GT - Better than both...
A 512mb 8600GTS would do better in terms of when playing games makes texture loading much faster rather than the 320mb
No man, the 8800GTS 320MB is way much faster than 512MB 8600GTS