A small suggestion from me, please don't go with XP-64. Been there done that and virtually no body supports it. I went back to XP-32 till Win 7 came out.

eBay is a good source for pricing, I have never been screwed on hardware, nearly everyone has a return policy.

I got my ASUS Crosshair gaming motherboard for about half price, with a dual core AMD processor. At the time it was about the best for speed with an AMD. ASUS also had one for Intel (which was faster). I am still using it even though ASUS is now up to Crosshair Formula 4. I am not a gamer, I got the board for its speed and flexability.

Good luck with your future endevors!!