Building an OBIEE Test Lab

About 1.5 years ago I bought myself a nice little desktop. The only issues I've had with this computer over that time are the OS upgrades (Ubuntu). It has been an outstanding machine. I currently have 3 "computers" running, 2 Windows VMs and the host machine. I've had upwards of 5 running at once. That's with only 24 GB of RAM. I plan on upgrading to 48 in the near future (max of 96).

One of the motivators for buying the machine was the recent (at the time) release of OBIEE 11g, which required significantly more power. I've installed OBIEE 11g a number of times in virtual machines, but usually just put everything on a single machine (Oracle Enterprise Linux).

Now, I'd like to build out a machine for each component. Why? I have no earthly idea. Fun perhaps?

So here's my starting point: