Just overclock the i7 920, it overclocks decently if you have the C0 stepping, and even better if you have the D0 stepping, and with overclocking it will match any CPU in the same line of CPUs up to the 970/980X/990X which are 6-core CPUs, so those are out of reach. The best upgrade you could get without swapping your motherboard is an i7-960, and that's the same CPU as the i7-920 except it's clocked at 3.2 GHz instead of 2.66. That's a very easy overclock for a 920.
-What is best in life? -To crush your enemies, see them driven before you, and to hear the lamentation of the women.
no i dont even have anything, he is giving me everything in the antec case with i7 920 and gtx 680sc and all the other bells and wistles for 200, i have known him for 12 years, he is a console guy and i am getting into pcs.