Locations would help a bit. It seems as though your brother wants to live close to you, Maine is a pretty decent size. I'm willing to bet a bunch of bigger schools have more programs for special needs, so I'd look into the southern half of the state for sure.

Then you have housing to worry about, and job opportunities (unless he's remote or has something in the works).

I do not need such programs for my family, so my knowledge of them is very limited. With a little for information provided, someone else may be able to help you better though! Good luck!