If you just plan on gaming with this PC I would get the I5 4670k CPU. You will save a 100 or so dollars then you can put that into a newer GPU. Like a GTX 760 or GTX 770. There is no reason really to get a I7 CPU unless you plan on streaming or doing video editing cause games will not take advatage of the hyperthreading in the I7.
NOTE: If you do get the I5 4670k CPU and upgrade the GPU to a 760 or 770 you will need to upgrade your PSU. I would get atleast a 650w or higher just to be on the safe side.