vital pants, take my (and probably many other's advice), build it yourself. I mean, even if you don't have much experience when it comes to this, you could get a better PC, for a price (maybe) less than what you already pay. All you have to do to build it is connect the right wires, and install the operatingsystem (OS, like Windows).
I'd go for the AMD 64, but that's just me, you ought to wait and see what the others say, though. You shouldn't take what I say into too big consideration, and you should wait to see what the more experienced people have to say.
That is all.
Here's the link for the AMD pci x board. It should be available every where in a week. They released it to their distributors 11/17/04. http://www.asus.com/products/mb/socket939/a8nsli-d/overview.htm