L.:
I'm not sure that my information will help, but did want to connect with you.
We recently adopted a 3 year-old with behavioral and sensory issues. As she is over 3, she is now receiving services and attending a preschool program through our local elementary school (Oak Park). Each elementary school district is in charge of 3-5 interventions, so CPS should have something for you once he's 3. Sounds like you already know that as you've made contact with them already.
Unfortunately, we haven't located any other great preschool options for ourselves (our daughter's symptoms are pretty difficult). As an alternative to a preschool program, you might want to find a sitter with experience with ADHD. We found a good sitter, using Sitter City. They have specific items where a sitter can mark that they've worked with kids with ADHD or other special needs and you can search by this. Alternatively, you could make a post saying that you are seeking someone with this experience.
Sitter City was inexpensive and easy to use. It also helps you keep track of responses and past messages. We found an outstanding person as well as several other great candidates.
Are you close to Oak Park at all? There is a good support group for parents that meets once a month, at night. It's run by an O.T. (who works with older kids) who is also a parent of a special needs child.
I would be interested in knowing what your experience with U. of I. is and who you are working with.
I hope that something here was useful. Good luck. Feel free to email me off ____@____.com
T.