Shorty,
I'm assuming you already are aware that you can get these at just about any Chinese bakery on Argyle or in Chinatown. (Just mentioning this in case you don't know that the bakeries are where to look for these.)
If its got to be in the suburbs and you are north, you might want to check with Richwell Market on Dempster in Morton Grove. I have gotten the bamboo leaves there before to make these. Check ahead to see if they have premade zhongzi. If you are west, I think you could pick up some at the International Mall in Westmont.
By the way, they aren't that difficult to make, although getting the shape right takes some practice.
"I live on good soup, not on fine words." -Moliere