Title says it all, read on if you think this an odd request.
I realize that this question is quite unusual, but ssh and FTP are the only access methods for my Mac.
Why I'm doing this:
The situation: I have an outdated iMac, whose video card fried about a five or six months ago. The screen still turns on, but it nearly impossible to see at all, with the image not changing much at all after the boot finishes. Luckily, I was using ssh and FTP on it before the crash so the thing wasn't just bricked. I've been using it as a server running Mac OS X 10.8 since the crash, storing files on it and running a few small game servers for my friends and I. One of the game servers I'm trying to run requires Java 7, which I can't upgrade to via terminal so far as I can tell.
What I hope to gain:
I know that running a command line based *nix installation would greatly increase the available space and memory for the things that I'm actually using, and quite frankly I am tired of the limitations for ssh/FTP only access with a GUI-based OS.
Any advice/guidance is greatly appreciated, thank you in advance.