A good place to start is with NewEgg
. I also would recommend looking at CPU Magazines website
which has a wealth of information and may help you find good price comparisons or better components.
I own a Dell and ever since they bought Alienware, the systems have not been the same as building your own rig. There are also quite a few good websites that can build the same rig for you on the cheap. Cyberpower
Let me know what you think!