change the HDD to a samsung spinpoint F3 1TB, that CM v8 isn't a great cooler for the ci7 920, maybe get a thermalright ultra 120 extreme or a prolimatech megashadow and some decent fans.
For the price of those GTX275's you could get a HD5870 or almost 2 x 5850's Both options would use less power, produce less heat have DX11 and eyefinity.
The HD5870 would be slightly slower than 2 x 275's but IMO the pro's outweight the con's.
i picked the r2e because i can get it cheaper then my original choice p6t deluxe v2. i have changed to 2x HD5850's, and changed my fan to the thermalright ultra 120 extreme. i have tried getting parts through newegg but they only ship in america and i live in australia so that is my biggest issue. would the r2e fit in the antec 1200 though? i have heard it is slightly bigger than other mobos. thanks for your reply