As mentioned, Chicago Firewood is a great bet for chunks, which are often better than chips. I have seen Apple chips, though, at Menard's, who also have had Cherry and Maple chips, and often have hickory and mesquite chunks.
2601 N Clybourn Ave, Chicago, IL
I purchase apple wood (chunks, not chips) at Chicago Firewood. The address is 1300 N. Halsted, but they're actually in the back of that address. They also sell oak, hickory, cherry, etc. That's where I always go to get wood for my smoker. Here's a link to their website: http://www.chicago-firewood.com/index...
If you absolutely need chips, you'll have to phone them to see if they can help.