The only was to be legally runing the games in your center is to get each publishers liscense agreement - Valve you get through them but if you join iGames you get a discount from them, EA and others you get directly from iGames.
All of the info you are asking about in the GAMERS forums is located in the private Gaming Center Owners forums so if you have already joined iGames as an Honoray owner please post these questions in the private forums and you will get tons of responses and look through the info already there for you with this info and so much more about starting and runing a gaming center.
If you haven't signed up as a iGames center then do so it is so worth the $25 a month honorary membership fee.
See here - http://www.igames.org/regions/MiniAboutView.asp?MiniID=171&AssetID=1190
Co-Op Advertising and Marketing Committee
Game Support Committee Member
I contend that for a nation to try to tax itself into prosperity is like a man standing in a bucket and trying to lift himself up by the handle.
-Winston Churchill