What about kindergarten?
Ideally, I think it would probably be best if the child could have home schooling, though I realize that is typically not feasible. The problem is the noise at the school, particularly the cafeteria. I know the teacher may not realize that the noise is torturing his ears, and may only know that he seems distracted, and may not even correlate his being distracted with the cacophany going on in the room. I kind of think that if they had the hypersensitivity he has, then they would be very easily distracted, and more so than he is. I don't think the special ed class, with its noisy, frustrated, and screaming kids, is a good place for him either. The explosive sort of noise would cause him even worse torture.
I would have the following recommendations:
Just anything that could help the kids better grasp concepts on a more tangible basis - things that they can see or feel.