Which game do you want to host? Share what you find out also. A lot of other people are wondering the same question. The more players the more server resources it will need.
As what other membres said, it depends on your game type/requirements.
I suggest you to check pcpartpicker.com/guide/ and see what people vote for and read comments.
That website is also very helpful if you want to build your own gear.
I disagree I contacted them regarding an accessibly issue and let's just say they didn't care too much. Even though it was COMPLETELY on their side as I used TcAdminx and other control panels just fine with my accessibly tools.
I am sorry but if your intentionally going to do such things then I don't spend my bucks there.