I don’t know about the disability services but you may want to take a look at Hope College in Holland MI and Kalamazoo College. Having a more conservative student body seems to be very important to your son. Hope is a Christian LAC with an enrollment of about 3400 that seems to be more moderate than some of the really conservative evangelical colleges. It has quite strong academics and imo is somewhat of a hidden gem. Holland is very charming and the college is located adjacent to the super cute downtown area.
My info on Kalamazoo is more anecdotal but I have known a fair number of more conservative leaning students who have really thrived there. I’m not sure what the overall vibe on campus is though.
Both might be geographically well positioned if you are coming from Illinois and at least worth a look.