Need of a contract for Mobile Home Owner Financing

Hey guys!  We purchased and are rehabbing a mobile home park in Missouri.  We are going to owner finance trailers to individuals instead of renting them out.  I am in need of a owner financing contract that has the extra stipulations that go along with a park.  Examples would be you can't move the home while you still owe a balance, etc.  I'll be honest, since this is our first park, I don't know what I don't know when it comes to these contracts.

Does anyone have a solid contract they would share? Or even better, a good lawyer who specializes in parks that can write one up and guide me through what I need to be aware of?