All good points with the past 2 posts on this subject. Does this guy wanting these machines know that you are 15 or did he just come across your website? I don't know many restaurant owners who would want to get into a contract with someone underage.
Here are some other things to consider. Do you know how to fix video games? Things will break including monitors, etc. that will need to be serviced. If he is wanting 12-14 machines, you are also going to have to supply games probably like cranes, prize merchandisers, etc.. If you can't work on them yourself, are you going to be paying someone to fix them? Since you don't have a license, who will drive you to the location when stuff breaks down(which it will)?
Normal contracts for games like this will include a split which is usually 50/50, 60/40, 65/35 type thing. I don't know any place that is going to sign a deal where they don't get any money until a minimum is hit.
Sounds like you got a good head on your shoulders, but stick with your bulk vending for now until you have the capital to go ahead with a full game room of stuff.