I did this a couple of years ago at
www.windycityflyers.com. It's a bit out of town, you need to take the train north for 25 mins, and then a cab.
Last time I was in there I tried with a FBO at Midway, but was way too expensive, especially since they only did 3 hour blocks. Also, they say you can end up waiting 30 mins for takeoff, and that's expensive when you're paying by hobbs rather than tacho meter.