start your own professional basketball league in the US, for 17 and 18 year olds. they will play against each other, but have no restrictions on practice time, coaching, etc. provide classes so they can get their GED by the time they leave the league. this will only be for those players who are willing to bypass college (and high school) eligibility by going ahead and turning pro and staying closer to home. sure, you won't have a very large pool from which to draw. but in a few years, you could become the feeder league to the NBA. watch out, though, as the NCAA will do everything in its power to snuff you out (probably including getting the NBA to rescind the age limit).
if this becomes a trend (going to europe), i wouldn't be surprised to see a non-NBA sanctioned pro league for upper-teens in the US, probably started by someone like sonny vaccaro. it's not a far reach from the current AAU system.