For a prebuilt computer, I would recommend going to ibuypower.com. They outperform, and are cheaper than your normal HP, or Compaq, you can choose your own parts too.
What's the difference between my computers and HP computers, save for the fact that I know what I'm doing, offer a better warranty, know what I'm talking about and use better quality parts?
But other than that?
I'll bet you can find a really skilled VAR down there that can build you a top notch computer.