So I was low on budget, couldn't go beyond 1500 dollars with everything, including keyboards, mice and even speakers.
This is what I currently I have, I will only list the case, because the other things are really irrelevant to me, except maybe the monitor.
Anyway, here we go
Case: got at 80 dollars
Antec Mini 300
This fits all my components nicely, and it has a mesh to filter out the smoke. Another nice thing about it is that the PSU falls in at the bottom of the case away from the other components.
CPU: got at 240 dollars, almost bran new.
i7 920 @ 3.8 Ghz
Ram: got at 160 dollars on sale
G.Skill pi series
1600 mhz PC3-12800
3x2 GB TC kit
Actually looks like a pretty good build. You got the cpu used? The only thing that concerns me is the case. It's pretty small for something with this kind of power and that will be so hot. The first chance you get upgrade to an Antec 902 or HAF 922.
I agree with saint19, you will want to look at a better case, the TT V9 is good for the price, or at least a better CPU fan coz the stock intel one is average as, a friend of mine is having big overheating problems with his, and if you are going to be running windows 7 then definately consider an ATI 58xx for Dx11.