If you REALLY care about squeezing the last ounce of FPS out of your rig... I would recommend ditching the i7 2700k for an i5 2500k, and splitting the money saved on a water cooler like corsair's H100 or H80 (These are super easy to install - its a out-of-the-box system, plug and play ) I own the H100 myself...
And push you proccessor to 4.6-4.8 gigaherts... whatever youre more comfortable with.
Dont worry that youre going from a 4 core to a 2 core processor - There is no game out there that can use more then 2 cores... in fact, there are none that can use 2 cores effeciently at all.
The rest of the money would go into upgrading to the best video card on the market right now the 7970
Thanks to everyone for the answers, about the i5 2500k recommendation, i prefer to stay with i7 CPUs and about going up to 4.8ghz i think its not worth it because it wont affect that much to upgrading many fps in games, the video card is what really matters
The only things i may change in this build are the graphics card and the mobo since i dont have enough information about the DZ68BC and its overclocking performance (@4.2ghz)