That sounds like an awesome idea! IDK what the actual market would be like for a "exotic petting zoo" but I'm sure if you marketed yourself correctly and were able to create a safe environment for bot the animals and the people (kids especially) you could have great success in it! I wish I had had someplace like that when I was a kid where you could really get up close and personal with animals that you just don't see every day!
just my .02