I agree the GTX 560 Ti is almost the best card you can get on a budget if you go NVidia for Gaming.
but the question I have to ask you is what resolution do you plan on gaming at?
I game at 1080p with max to ultra settings so I use a GTX 580.
If you plan on playing Battlefiled 3 you will want the GTX 560 Ti. or at the Minimum the GTX 560 non Ti witch is the recommended card to have for the game.
check this one out from newegg.com its a GTX 560 its just a less powerful than the GTX 560 Ti he recommended.http://www.newegg.com/Product/Product.aspx?Item=N82E16814125383
its $30 less than the Ti model from the same manufacturer.
And as far as power supplies go you might want to consider a Seasonic 80plus gold rated Power supply, that seems to be a popular manufacture of power supplies used by Toms hardware in there system builds.