CPU Cooler: Switch that for the Coolermaster Hyper 212. It's $15 cheaper, and it's one of the best HSF out there.
PSU: Rosewill isn't known for quality. Switch for a Corsair, Antec Earthwatts, Seasonic, OCZ or PC Power & Cooling. My personal favorite recommendation right now is the OCZ StealthXStream 700W for $55 after rebate.
GPU/OS: I think there's a combo with Windows 7 and the XFX 5850. That'll save you some money and get you a great warranty on the card.
CoolerMaster are also great PSUs... i would also consider Corsair but i belive the other members know more than me about those...
Monitors?? Why not purchase a plasma HDTV and plug it to your computer?? I do it myself and it's a good idea... specially GREAT for games you'll see
@grossemesser, a HDTV is normally much more expensive than a monitor, and you get lower refresh rate, lower response time, worse contrast ratio, and most of the time a crappy resolution.
getting a HDTV with the same specs as a monitor costs an arm and a lag, so i'd advise against it.
i have benq e2200HD monitor. id recomend it a hundred times over. its cheap, 21.5inch with 1080p resolution. 2ms response time and 10,000:1 dynamic contrast. looks excellent, and very well priced. LGs own 21.5inch is also a very good choice.
And don't get hung up on a modular because most of the good cases have a bottom mounted PSU, so all benefits of the modular unit are eliminated by the cords being at the bottom and out of the way already.