We would recommend that you ensure that you have enough disk IO for the Virtual Machines (We do suggest that you use enterprise SSD’s). We do keep the OS and Virtual Machine disks separate.
You can create fully working syspreped machines with the licence key and the VMConfig service as you would have done on WSP. The variables in sysprep are the same as WSP. We currently dont have a template for use on 2012 but if you have any issues please let me know.
At the moment i have not made a full guide on the template setup for SolidCP virtual machines but it is on the list. If you need this i can bump it up a little and have it done by the end of the week.