It's not in a nice location but visit Chi Town Vapors
Showroom Location
You could also visit Cigtechs in Hanover park.
Welcome to Cigtechs - Quality electronic cigarettes They have samples of all their flavors.
If you are flying into Midway airport, there is one down the street on Cicero called Quitters that's worth stopping by. They carry Roar juices.
www.quittersllc.com
Most of the rest of the ones I've found in the city are just head shops with a limited selection of juice and equipment and since you've been on here for 200+ posts, you probably know more than they do.
While I understand your excitement, keep your expectations low. Personally, I think vape stores are pretty underwhelming.