get rid of the 780i and get a 750i ftw or even a ip35 if you want to get a bargin. instead of the e8400 chuck in a q6600 with the extra cash u just got from the mobo.
that ram is overpriced. get a decent 4gb (if vista) of sgskill ram for about the same price.
also get some tx-2 thermal paste its the best atm. Also if you are thinking about a aftermarket cooler the xigmatek rifle 120 is good.
with the grpahics cards, ive heard the 4870x2 is better than the gtx280 (source cj who provided with first gtx280 benchies). and that isnt coming out untill after that other cards are out (18th).