drop the 790i, if u think ull sli get a 780i or 750i. if not get a biostar p45 or a asus p5q delux.
get rid of the 2 9800gx2's, get either 1 or just get a gtx 280. or a 4870x2 (if u get a 4870x2 dont get the 780i or 750i)...
get a corsair 750 like said above.
id get some different ram, alot of ppl here like the ocz hpc but i like patriot vipers personally. 4gb of ddr2 800 or 1066
the nzxt tempest is a better case imo. or the antec 1200 if u want to spend that much
i would get a quad core for being future ready
oh and get this cooler:
Newegg.com - XIGMATEK HDT-S1283 120mm Rifle CPU Cooler - CPU Fans & Heatsinks
with this backplate to reduce mb stress:
Newegg.com - XIGMATEK ACK-I7751 Retention Bracket - CPU Fans & Heatsinks