The only places I've seen them locally are the Jewel stores in Evanston and Skokie and Hungarian Kosher in Skokie. That Pickle Guy has an equally food refrigerated half sour that may be easier to find - in addition to their excellent Hot and Mild Muffalatta mix.
I don't know if they have them there, but the most likely place you'd find them in the western suburbs is at Schmaltz Delicatessen in Naperville. www.schmaltzdeli.com
You could also try contacting Ba-Tampte through their website to ask. www.batampte.com
1512 N Naper Blvd, Naperville, IL 60563