I could use some help on what I should buy for my next build

I can't AMD anymore, I'm going back to intel but I wanna know what Parts to buy. I can't decide and I have 1vs 1 battles and I would love some input if you guys could.Processor :E8400 or Q6600Motherboard : Evga 750i or 780i worth it?I have no clue what's the difference from 750i, I been out of the gaming market since I got my ps3/xbox 360 and now I miss my mouse and keyboard.At the moment I have a AMD 6400 x2 and Asus 750i. The board isn't too bad, but what I like on the 780i is true 16x16x sli but I hear from some gamers sli is a waste of time.I'm really just running into a wall on the processor and motherboard. So far I have the1000 watt modular PSUGigabyte Case (slick looking case)8 gbs of Corsair DDR2 Dominators260 gtx (Nvidia) I want to sli these 22 TB's of Hard drivesJust need help on which processor Motherboards :), any input will be greatly appreciatedI could use some help on what I should buy for my next build
My opinion is the Quad. I don't know about those motherboards I perfer the intel chipset for stability.