Without spending too much more, you can bump up to a E8500 or a X3350 [currently cheaper than its twin.. the Q9450] and stick with a cheaper, single GPU solution for now. A 8800gt will perform more than well enough to handle any current games.
It has already been proven that with gpu's more powerful than a 8800gt, video performance is severely limited by the speed of the cpu.. and not necessarily the number of cores. In-game Crysis showed a mere 1-3fps difference between a Q6600 @ stock and a E6700 @ stock [mosty due to the larger cache of the Q4..and not the extra cores]..yet both systems can yield over 3k point increases on synthetic benchies when OC'd. So, in short.. not OC'ing the cpu, it becomes an immediate bottleneck when SLi/Crossfire is introduced to the system. Why pay for a 20-30% increase, when your system is already capable of giving it to you?
Bottom line..its still your $$ and decision. Just my
on the matter... hope it helps in your decision.