We raised an autistic son in CA, but were always aware of what was going on in other states, since being transferred was always a possibility. Utah has some great programs for children, but once they turn 22 and fall out of the school system, they will be put on a waiting list for services that can be years long-like 10 years long, I am told.
The trick is to put him on the waiting list while he is still in school, so that when he moves to the adult services, he will be at or near the top of the list.
Kudo's to you and anyone who raised an autistic or other special needs child. Having been down that road, I know how rough it can be. We lost our boy a few years back to a siezure, and while I don't miss his tantrums, I sure miss him-everyday.
As far as a good place to live, just avoid some of the areas in West Valley City and near downtown, and you should be OK. If you don't mind a bit of a longer commute, Lehi/Saratoga Springs has some great deals on newer housing, the area was growing like crazy and now that the slowdown has hit, many homebuilders building on spec find themselves with a glut of houses, which they are trying desperately to dump.
One new area that you might want to avoid is the Traverse Ridge between Draper and Alpine. Incredible views, but the wind blows nonstop and there have been some major issues with hillside stability in parts of that development.
No, I'm not a realtor, but I am an insurance guy, so I see a lot of what goes on in the north end of Utah County and the far end of Salt Lake County.