1: i dont see why to get a i5 2500k when a i5 3570k is better and has more features.
2: id get asrock extreme4 z77 board for the i5 3570k
3: id get a asus 7850. performs better and uses less power
4:for the psu, a good 600w is enough for crossfire. id get a xfx 650w, pc and power cooling mk3 600w, or a corsair tx650w v2. get whichever one is cheaper. they are all good
it will run pacman