New ESXi Setup

I just purchased a Cooler Master Cosmos case and I would like to do an AMD build to host 6 to 8 VMs on.

VMs:
1, Windows Server 2008 (Running IIS)
2, Windows Server 208 (Running SQL Server)
3, FreeBSD (Running Apache)
4, FreeBSD (Running MySQL)
5, Ubuntu (Basic Linux Desktop config)
6, Windows XP (Used w/ a thin client for daughter to boot into)
7, OS Unknown (Used as a file server w/ 6 1TB hard drives)
8, Oracle Linux

Plus maybe 2 or 3 more for testing applications on older operating systems or configurations.

I was thinking an AMD opteron (8 cores) and 32GB ram would do the trick. I'm not sure where to go from here. I'm worried about spending 2k on a setup and finding out it's not compatible w/ ESXI.

Can anyone share their AMD builds which would support what I'm trying to do?