Hello Ralphferro,

You don't need a dual-processor motherboard. Anything you build today should be multi-core (which is sufficient for a lab). If your processor and motherboard support virtualization extensions (Intel-VT or AMD-V), then you can even run ESX in VMware Workstation. Workstation 7 even supports this without manual .vmx file tweaking. Another good place to start looking is the below article:

http://virtualgeek.typepad.com/virtual_geek/2009/01/updated-homebrew-esx-hardware-list.html

I hope this helps.

Don't forget to use the buttons on the side to award points if you found this useful (you'll get points too).

Regards,

Harley Stagner