I don't know if there really is a need for a one-stop-shop for CE's in Chicago. There are plenty of places that offer classes, and they all have their necessary equipment and instructors lined up... There are also plenty of out-of-town instructors that come through here to teach seminars, and it appears like they never have trouble finding a venue for their seminars.
However, I would start there: ask some of these people that come into town if they are interested in a space where they can give their courses. They may, for instance, feel like some existing venues are too expensive or too small, or whatever.