Be careful with the AAU circuit. There are some very good programs and some that are not. Geno Auriemma talks about AAU and is spot on. Something to the effect of kids showing up just for games, no practices etc and how that is ruining youth sports.
At 8,9, 10, 11 years old etc there HAS to be an emphasis on practice. Games are great, but practices with a good coach is imperative.
My son played AAU through Hoop Heaven in Bridgewater at an older age than your son and I thought it was good. They played in a league with similar skill level, but it was only 1 game a week, occassionally 2 and a few tournaments in Madison (i think), Tinton Falls, and at Hoop Group (Mike Rice is there now), and one weekend at Spooky Nook in PA (unbelievable facility!).
For my son, it was definitely the right skill level.
If the AAU team is bringing in kids on the weekend for a tournament, its not a good team to be a part of.