Lease Option Contract


I recently 3 duplexes and one of them has one side occupied with long term residents.
At this time I do not care to be a landlord but I also wanted to help out the tenants in being homeowners.
So i offered them a deal to lease the property for 24 months at a set price, I would pay the insurance and taxes and closing for the 24 month period.
I need to know where I can get a contract for these deal that would be legal without having to go pay an attorney.
The property is located in Missouri.

Any help is appreciated