I don't know if you have seen the other thread about Asperger's, (which I know is slightly different, but similar question) but here it is:
http://www.city-data.com/forum/iowa/...-children.html
In that thread, a parent of a child with Asperger's recommended Iowa City schools, and I'm inclined to agree. I will admit that I don't know much about the special education programs other than that they are there, but overall the schools here are pretty outstanding, and I'm sure the district takes care of its special needs students as well. If you want more specific info, I'd contact the Special Education Dept., here is their website:
Welcome to the Iowa City Community School District
Also, the University of Iowa (also in Iowa City) has a program educating teachers and parents about autism and seem to have quite a bit of information about autism that they can provide. Their website is here:
Regional Autism Services Program I would assume that some IC area teachers would have consulted with this group but I don't know that for a fact, again that is something you would have to ask about.
There is also the Autism Society of Iowa, which has meetings and tries to raise awareness for autism in the state - I don't know if this will help but I thought it might be of interest:
The Autism Society of Iowa
I would say that overall, a larger district would probably be better, as they have more resources and larger special education programs than smaller districts. Any decent-sized city (above, say, 40K people maybe?) should have a district that could work for you, you would just have to ask them about it. I think Ames schools have a pretty good reputation as well and if you wanted to be closer to Nebraska, that might be something to look into.