lol... you should have asked this last week.
This past weekend was NARBC at Tinley Park, the biggest reptile show in the area. As with all reptile shows there were (too) many ball pythons of every variety everywhere.
As for anyone who lives IN chicago, I don't know of a single one.. sorry.
My guess is you're either going to have to make a long drive or ship. There are plenty within a few hours drive of Chicago.