I want to be able to play battlefield 3 on ultra settings while recording with FRAPS, and get a constant 60+ FPS, I was looking at dual AMD Radeon HD7970, will this do or is it a bit of an overkill?
A 680 would be plenty. A 670 should do it. If you want 2 it will run faster and better that way and you should be able to force it to 32x AA to look yet even better.
A 7970 should be great too.
the 7970 is faster. And it would be better to get a 680 SLI than a 690. Personally I would go with the 680SLI/690 but I am a Nvidia fan. And as said BF seems to like Nvidia better than AMD.