i'd say go with the 6600gt if you dont want to spend a lot of money but if you are willing to kick in the full $230 like you said than i would go with the 6800GS.
LoL we are talking about videocards here and macdude is worrying about how big the other guys sig is rofl that is hilarious.
New build in progress, but this is what I got for now:
-AMD x2 5200+
-Asus M3A78-EM AM2+
-Buffalo 2x1gb ddr2 800
-Hitachi 250gb Sata HDD
-Antec Minuet Case w/ 350w psu
-Windows 7 Home Premium 64 bit