What to look for in web host providers if I were to host a video game?

My game is a real time versus multiplayer game. It would constantly be sending input to the server to track the players position's and I was wondering what it would cost to host something like this. Would I be okay to use something like http://ift.tt/1hzoLZn to begin with? I would expect < 50 players on at a time at the start. Also, is there something in particular that I would be looking for in my plan? (Storage, memory etc..) Thanks in advanced!