Not a whole lot out there. I am in this area. Stonehedge Farm in Union Grove, WI. Ken + Eric Dierks train out of there. Lake Geneva equestrian center has Brad Hall. That is quite a bit west though.
Ken and Erin Dierks are in the area, Eric is Ken's brother. I have been absolutely thrilled with Erin and Kenny! They are well known in the area and travel all around the midwest. They do not have a specific barn that they train out of but travel to different barns for lessons and training.
A good place to start would be to call Erin to ask where she and Kenny frequent often and see what would be in your general area. Contact information is on their website http://www.erinandkennydierks.com/
I second Ken and Eric, both good coaches. Ken's dad Klaus also gives lessons out of Stonehedge. Brad hall is a good coach at events as well. Another person in the Chicagoland area that I can't speak highly enough about is Jamie Price, but she just moved to PA.