Not a bad build actully are you looking to overclock? If so there is a board that is about 13 bucks more that i've seen reach 3.6ghz on an E6300.
The ram is good choice..G.Skill is an excellent company. The HD is great. The Monitor is an awesome choice. PSU great one there but id suggest the 400w since itd be fine. Case is good enough.
NOW thing i recomend you do is take the EVGA version of the 7900GS. I trust EVGA and its been known to yield higher OC's as I have mine running at 625/835 from the stock 450/600 without volt mods. It will save you a few bucks.
As for the cooler my stock EVGA cooler keeps my card ice cold at 49 load OC'd.
E6300 w/ Arctic Freezer Pro 7 @ 3.6ghz 1.4Vcore
Antec 900 Case
EVGA 750i FTW Mobo
4x1GB of G.skill DDR2-800
2 8800GT in SLI
22" Samsung Syncmaster
1 250GB WD and 1 Seagate 7200.10 in RAID 0
Corsair 520HX 3DMark06 Score: 13900