Free is always great when the solution really works but does it really do everything that you want it to do? I have stopped going for free software no matter what it is only because I never get the support when I need it (you get what you pay for).
I found HMSPANEL linux control panel for my VPS setups which runs on top of HyperVM virtualization technology and I couldn't have asked for a better setup.
The prices are excellent for both and the support has been excellent from both.
Check both of them out:
www.hmspanel.com &
www.lxlabs.com