Looking for multi family for son to house hack

I'm starting to search for a multifamily unit in Madison Wisconsin. My son lives there and will be living there for a minimum of another year and I'm hoping for him to find something and get moved in next summer so he can rent it to college students through the following year and then he would be able to get a loan where it's 3% down because he would live in one of the units with roommates and then he would also rent the other units out. Just starting the search, but any recommendations of where to begin would be great. He doesn't have cash so hoping to do it with the least amount out-of-pocket as possible, but I would be able to help him a little bit, but not a lot