Here's the topic where free search services are linked. You can doctors and therapists through the search services or find a local support group or autism chapter through the search service, and then get the advice of locals.
http://www.autism-pdd.net/forum/forum_posts.asp?TID=19141&am p;KW=expert
Hopefully other Illinois members will see your question, too. I know we have members in the Chicago area.
I live in NorthWestern IL right on the IA border.