1. dont take Smooth's advice for that monitor. You don't that huge resolution unless who are truly hardcore. It's obvious from this thread, you are certainly not.
2. you CERTAINLY dont need 1000W PSU, unless you are doing crossfire, SLI, or really high end GPU [GTX 280]. Depending on your final build, I say 400-600 W
3. do you like money? do you also like performance? get Radeon HD 4750 or 4780. Cheaper, but still awesome cards are also there [HD 3750/80, 8800 GT [or GTX] ]
4. Get a nice almost-3Ghz dual core from Intel. Unless all you'd do is gaming on that PC, which I doubt, CPU is really the most important component in terms of performance for your every day activities
5. Nice case, kb and mouse...dont really know too much about cases and mobos, unfortunately.
6. avoid $2000 or more pre-made gaming rigs no matter what...which is pretty much all of them :/
You only need to spend $1000-ish to get REAALY great computer. This doesnt include monitor, which is most expensive portion, unfortuntately
for more:
http://techreport.com/articles.x/15009your welcom, bitch