A couple of years ago, I biked up from Central Indiana to South Haven, MI. I camped at Van Buren State Park and Warren Dunes State Park, both on Lake Michigan and both very nice parks. South Haven is a very nice town, and you have a super resource in that area in the Kal-Haven Trail State Park, a rail-trail between South Haven and Kalamazoo. (I also camp with a hammock, a Hennesey. The state park personnel not only didn't mind camping hammocks, they allowed me to bike around the camp ground to pick the camp site with the best trees.)
I will also say that Michigan car drivers seemed to me to be especially accomodating to bikers. I was impressed. Enjoy your bike-camping trip. You live in a very nice area of the country.