I'd suggest Hilton properties - they have a "Guest List Manager" which lets you book rooms for multiple people, enter rate codes, view reservations others have made using your rate code, etc. If you call, you can see about getting a special rate. I'm not familiar with Chicago, but depending on the age of the kids, you could amuse them at a Build-a-Bear either by just showing up, or arranging a party in advance. The kids select a sewn-together but unstuffed bear or other animal, and get to help stuff it, fluff it, dress it, etc.