The Asus motherboard I had turns out to work fine with ESXi just had to set the SATA controller to AHCI, the onboard NIC was not supported so I had to order a cheap Intel PRO 1000 card for it to install. Next phase is to get a Dell Perc 5 which will hopefully work on my motherboard for a larger data store and increase RAM to 8GB. The entire system will eventually move into a nice NORCO 4020.
I should have a pretty nice whitebox for learning purposes once this is complete.
I plan to learn Vmware, Server 2008 with Hyper V and how to configure different RAID levels and storage.