if encoding and video editing is your main concern then a gtx 570 would do you justice....if gaming is more of your thing then a gtx 670 would be what you want...the 570 does better for "CUDA" applications like with premiere then the 670 but the 670 will be faster in games.
Thanks! I am looking to have something very balanced. I will probably edit more than game, but I want to be able to play games such as BF3, Crysis, SC2, and any newer DX11 games that come out. My editing needs are not as huge as I dont work with too many layers, but would love to cut transcoding times down and effects processing times WAY down.