Game server/NAS in home LAN party use. AMD Phenom II x4 965, 3.4 GHZ, 12GB ram, 120 SSD.

I know it is not a "server" but we use it to host our ModdedARK, 7DTD, Modded Minecraft games (though 1 at a time). We have a weekly Lan party with 5 players. I have windows 7 on the box for now due to being lazy, will be switching over to Ubuntu server 14. In addition I have been running my Plex server off one of the gaming stations/terminals. I would like to run 3 games servers at once (though only 1 actively being used at any time), Plex server, NAS for my Raspberry Pi media player to pull from.

I could add a 1TB HD and bump the ram to 16GB on the 965 x4 load up VMWARE, Mine OS, ubuntu and try this but looking for thoughts about it.

My friend puchased an older Xeon server on E-bay for $400 but I want to use up the parts I have laying around. It runs ARK modded and Modded Minecraft very well for our small group, but is it worth trying VMWARE for something this small? Is this just more then these old parts can do? I do not want to spend money on a server. I know I would end up building a dedicated rack mount server and just having another project!! but at the same time I do not want to waste time and effort on a lost cause with this 965!