You could save yourself ALOT of money by going with the i5-2500k and a standard ATX motherboard. You could probably save so much in fact you could afford to shove Crossfire 6970's in! (850w PSU recommended though, or 600w for a single card).
Also, there's no point filling all of your RAM slots with 2GB sticks. Just run 2x4GB sticks in dual channel so you have room to add more if its ever required.