VMware workstation works great for me. I run it all the time and a base install of Linux only uses a relatively small amount of memory. Of course that is very dependent on how nice your custom apps play - if they are GUI based or not optimally coded they could use up a lot of resources. Having said that I would have thought you could get at least a couple of VMs running on an SP.
I am running a Virtualbox and inside it a Ubuntu x64 13.04 and inside it a Windows XP malware testing setup (Cuckoo Sandbox) :wink: , I disable Unity as i don't use, it requires much more resources so just enabled default Gnome Interface.
I was expecting much from hyper-v but there were two problems. First i could not install the drivers under Linux mint or Ubuntu. Second even on energy save mode and without charging hyper-v made my surface stays at maximum cpu-load which inst good for long working sessions.