pls go for GeForce 8800GT 512MB DDR3 OC (eVGA) it may cost u 12.5 to 13K its really good for more info go thru the post posted by PhOeNiX LONELY PLANET, For Graphic Cards
All of them are of the same underlying 8800GT reference. Go for a cheaper deal, they'll all give similar performance(or get it to by o/cing). EVGA being an exception.
Ive heard the Gigabyte 8800GT overclocked edition is available under 12k as well, seems like a good deal. in any case i would advise u not to spend more than 12k on an 8800GT