The standard 460s are slightly slower, the factory overclocked 460s are on par or slightly better than the 6850, it really depends on which 460. However the 6850 is cooler, has a lower consumption and it overclocks very well.
Both are kinda overkill for your resolution, IMO a HD 5770 should do.
Nah nothing is overkill for me
I dont wanna play a game thats under 60 fps Hehe
Btw the 460gtx models that I'm planning to buiy are the palit ,Inno3d,and evga overclocked models and for the 6850 it doesn't arrive here till Christmas so I can still wait.