Sorry to add this late into the discussions but you spoke of Hyper-V, you can download the Hyper-V 2012 Core RTM free of charge and run your VM's on that. I run a Hyper-V environment in a clustered configuration and it works really well. I would say the only downside is that ESXi supports Linux and other OS's better, but it sounds like you using an all Windows Environment anyway.
You can download the tools to run on your workstation (must be Win7/8).
Just offering another option, it's got quite a low overhead as well.
Hyper-V does an alright job of running linux...at least RHEL and ubuntu. I've got 4 Ubuntu VM's on a Hyper-V server and they run great. Only thing that sucks is no updated integration drivers for Ubuntu, so you can't use Dynamic Memory.