Try this website:
They build the computers for pretty cheap and its custimizable. They even let you choose your motherboard and everything. I think this would be good for you because you seem to know what you want but aren't sure of yourself enough to build it. Very similar to me. LOL. But if you want a really nice OC'able computer those websites are quite good.
PS I think you blocked me on AIM. My sn is mrgreen4meandu. If you would like more advice unblock me. If not then don't.
Hope this helps.