Rest of build looks like a strong budget system. I would switch out your motherboard for a Gigabyte Z68XP-UD3H. Its a little more expensive, but It is much better quality. Also Get the 1st one. The cooling is going to be much better on that one, And also I think it is non-refrence design so it will be much more stable as well.
i think the xtreme3 gen 3 would be good because it has pci 3.0, it will be compatible with ivy bridge at release date,