Antarescomputinginc has an evga 8800gt for $296 shipped (pricewatch) running at 1800 hertz (superclocked). For a budget, several brands of the 8600gt are available at newegg for around $80-90 after rebate. Evga offers a lifetime warranty on some cards. For the 8800gt, your power supply will have to be rated 22-26 amps on the 12v rail(s). If more than one 12v rail, I would go for 18 amps minimum on each rail.