Ideal home VMWare Server?

I’m looking for suggestions for home “test lab” server to run ESX on. I was thinking possibly a HP Proilant micro. I certainly open to the idea of building something, as I have before, but I’m looking for something cheap(er) that will run about 3 servers (Win 2008, Red hat) in a virtual environment.
Has anyone had any experience with the HP proliant micro’s?