Buying new gaming computer please help!

Dear All,

I plan to buy my computer from Cyber Power PC
I being doing a lot of research for the past month and here is what I am planning to buy
Cost ~1700 USD

Here are my specs:

Case: Cool Master Storm Sniper
Power Supply: Corsair CMPSU-750TX
CPU: Intel Core i7 920
Cooling Fan: Cool Master V8
Motherboard: ASUS P6T
Memory: 6GB Corsair Dominator
Video Card: GTX 295
Monitor: 24'' Inch 1900x1200 Resolution (Maybe a 26''-28'' with 2560x1600 Rez)
OS: Window Vista Ultimate (I will install it myself)

0. Better places to buy computers than cyber power pc?

1. Is there anything bad about these specs?
because i plan to overclock my cpu and graphic card

2. Should i get a GTX 285 1GB or 2GB instead? if i am going to run on 1900x1200 Resolution?

3. Will there be a problem if i try to install Window Vista my self? finding drivers?

any helpful suggestions will be greatly appreciated =)

thank you!