From the descriptions Intel gives on the Core architecture, the i7 core self-overclocks during single-core applications (from 3.2 Ghz to 3.46 Ghz, supposedly), is optimized specifically for handling DDR3 RAM better than any other processors, and has a much better handle on using Hyper-threading tech.
On top of that, it has the largest on-chip RAM cache's, which has a quite noticeable effect on games in particular.
Since you are going for dual GPU's, I suggest the i7 anyway. It'll be able to handle them much better.
ALSO: Your profile name is noted, and I declare it to be awesome.