J.F.
I'm not sure where you're located but you might try Gymboree Play & Music. We have a School Skills class that is once a week - 2 hours drop off - for 3-5 year olds. Other sites may run this program more than once a week. It would be something for him to start while you're looking for other alternatives. We also have Art III classes that could complement the pre-school class - those are also drop off at his age.
You can get information about this class on www.gymboreeclasses.com.
J. F.