I think we are gonna stick with the 6870 because its newer tech. That and i read that with new drivers the 6870 is like 6% better than the 5850. Yeah the 5850 is cheaper but he was thinking down the road (like 2 years) he may add another 6870 when they are cheaper. I read 6870s crossfire better than 5850s too.
I thought about the i3 but it's only duel core. How would the newer games coming out (that utilize 4 cores) perform on the i3 versus an actual quad core cpu? Also wouldn't the Phenom be sort of more future proof, even though it's older than the i3? I mean if the performance with the i3 is really going to be noticeable then i'm sure he would pass on the future crossfire idea. I'm just paranoid about more and more things taking advantage of quad core down the line.
I think i will switch to that ASRock motherboard though. My only concern about it is that the ram i picked is 1600 and the motherboard supports it but only with overclocks? I'm not really sure how to overclock anything.
The i3 is a dual core, but it has Hyper Threading. This makes it effectively a quad core. http://www.anandtech.com/bench/Product/88?vs=289
As you can see, the 2100 is better than the 955 by a sizable margin in gaming. It's because of the newer tech.
As for the RAM question, it's easy. just set it to 1600MHz in the bios. Nothing to it.
Phenom's architecture is not as fast as the sandy bridge architecture in gaming, it might be better for multi tasking (the phenom) but in gaming the i3 2100 its a bit more powerfull as for the grafic card if u plan to Xfire your choice is more powerfull than 5850 that alone performs just a tiny bit slower.