I assume that you're doing this to avoid purchasing the "ESX" version of VMware that basically does do this, and a WHOLE lot more?
If so, then I would host your environment in a similar manar as the ESX hosts. In other words, use RH as a dedicated host, and make it as thin as possible, run absolutely as little as possible, and still be functional. Then run what you want on your guest OS's. This will give the guest the best possible performance.
IMHO...
Paintballer