The OP mentioned GTX 560ti in his post.
HD 6950 is a bit faster than GTX 560ti, anyway both cards are great for gaming @1080P you won't feel much difference if you get any.
HD7850 replaced 6950.
Well, the chart will do the talk
The idea of grabbing HD 7850 is very good specially the price is very close between it and the GTX 560ti.
For the CPU, I'd highly recommend Phenom II X4 980/975 BE these CPUs are the best for gaming in all AMD CPUs.