I've used newegg several times and had no problems. If you have not installed CPU's before into a MB, you may want to get it pre-installed. I bought a pair of opterons for my box and bent one pin. It was a "challenge" to bend it back.

I'm not sure if the windows world has much in the way of 64 bit software (including windows itself). The linux world has been running in 64 bit mode for around 2 years now with good stability. I have been quite pleased with the 64 bit architectural changes. They added registers which will boost speed more than you'd expect. AMD's built in memory controller has also boosted speeds. I've seen 2X performance over what I expected from clock speed increases. In my case, the 64 bit addressing was sorely needed as well. I and others in the EDA world had ported alot of applications to linux but customers would need to run on sparc machines for the really big chips. If your curious about what might need more the 4GB of address space check out my . web site .

I'd encourage you to set up the machine to dual boot. Surfing the web is much safer under linux/firefox and you will be amazed how many apps there are included.

Enjoy the new box
mike