Best version of OS X for Mini Server

I have a Mac Mini 2,1 (Mid 2007 C2D) that can run up to OS X Lion, officially. I'm planning to run it as a server for VPN, file sharing, media streaming and backups and am in a dilemma with which version of OS X to put on it.

Snow Leopard, Lion, or.. Mountain Lion using MLPF? (https://forums.macrumors.com/threads/1325709/)

I've heard the Mountain Lion is more stable than Lion but since it's being 'hacked' onto the Mac I'm not sure which of the options would work out best. Any thoughts?

rctlr said:

I have exactly the same machine.
I've found Snow Leopard the most stable OS for it.

Click to expand...

Ah okay, that's helpful thanks.

So did you try it with Lion and not find it stable enough then? I don't mind putting SL on it, but it does seem pretty old - there aren't any features you find missing for server use?

rctlr said:

The only thing that snow leopard could not do for me that lion could was icloud. For everything that you want it for snow leopard is the most stable and has lesser memory footprint.
I'm still using the machine for that same configuration.

Click to expand...

Thanks for that info. I won't need iCloud running on the server so think Snow Leopard sounds like the best choice