i think that going with linux as main os is a good choice for many reasons.
1. It free and open source.
2. It much more stable then windows. Can't say to much about mac as i have never used it as os on one of my comps
3. It takes a lot less processing power, ram and so on.
4. You learn a lot from using it
When i switched to linux as main os it took me about 4 days to get it working as i wanted i reinstalled it 2 times i think. and every time you are going to play a new game it takes some time to get it working if it's not coded in java or any other platform independent language. so mc won't be a problem. I have had some problem with modding for not so long ago when you added modloader it placed one class in a new map in an other new map. i never under stood why..
but some things like that will happen but i think that you should go with it.
i run minecraft IC² buildcraft and a white list server with the same mods with almost no problems.
As for what distro i would go with mint or ubuntu. test both