Wow that's gonna be a killer setup. I think you've chose the best parts for a great system. I'm not sure if you want to to SLI. The performance increase isn't worth the price increase at this point. In the future, when more games support SLI, it will be useful, but for now, 1 7800GT is powerful enough. Other than that, it all looks great!
AMD 64 3200+ Newcastle@ 2.2Ghz
1GB (1x1GB) OCZ Performance Series
ATI X700 Pro 256MB OC\'d 475/525
OCZ Modstream 520W
Samsung 914v 19\" 12ms LCD
SB X-Fi w/ Logitech Z 5300e