Here's my guesses:
For ultra + 60fps minimum framerate, get the GTX 670
For ultra + 60fps average framerate OR ultra - MSAA + 60fps minimum framerate, a 660ti is my recommendation.
For ultra - MSAA + 60fps average, you could probably even get away with a GTX 660.
well the 670 is quite expensive but if your budget is not more than 200-250 then i think a EVGA 660 2GB will be better for youhttp://www.newegg.com/Product/Product.aspx?Item=N82E16814130826
not totally sure but i think with this card you can run BF3 on Ultra with 60FPS at 1680x1050 ..