Correction: Stockfish 6 works fine on Linux, but I couldn't seem to find a way to download Arena on Linux.
I'm not sure about Scid vs PC, but I believe it works fine on Linux as well.
But just a question for the OP; why do you need this information? In my expierience, when I was at your level (OP), I needed very little computer work. Maybe just tactics and videos, and that's it! I analyzed my game with my coach (you can probably just ask people in the forums to do the same thing) and myself, so I didn't need much computer.
But that's just me. Maybe someone else thinks otherwise. Just my 2 cents.
Stockfish 6 works just fine on Linux also. Many distros have a pre-compiled version in their package manager.