Need some advice on windows server

hi Elitepvpers,

I need some advice with an Server.

What i have atm is this

AMD Quad Core 3.2GHZ
16GB RAM
100/100 MBps

Current system Windows Server 2008

Now i am going to upgrade it to this
Processor remains the Same
64GB RAM
500/500 MBps

Now onto the next thing i am configuring the server with VMWare Workstation so its acting like an VPS Host. It will Host some games/Websites

Now my question is what kind of Windows would be better
Windows XP x64
Windows Server 2008/2012 x64
Windows 7 x64

The VPS for websites will be running on Linux.

Why i also have Windows XP x64 on the list is because it doesnt put an lot of stress on the system. In my experience Windows XP is still faster then Most new systems.(except Linux).

With kind regards

Windows Server 2008/2012 x64
I think both of them have Hyper-V (this is the native windows virtualisation)
if you need help with that you cann add me skype: eragon-tobi

I am running windows server 2008 atm.
So it aint hard for me to turn on Hyper-V. So i dont need help with that.

However what should i run on the Virtual Machine?
Windows XP x64(For less resource use Such as RAM/HDD space)
Windows 2008 x64
Windows 7 Ultimate x64

Those are the Versions i have atm.

I am thinking of Running Windows XP x64 to run some Flyff Servers on it for testing purpose.
Since XP uses less then the other systems.