Owner Financing how to and pitfalls

[Ramon Mota]

Hi I'm new to selling property. We have a restaurant that is paid off and would like to sell. We received out first offer and they want owner financing. 

How would I set up a contract that protects my interest and will not force me to sell if they back out later. 

can I have them do a payment and make it non refundable if they don't have financing by the end of the term.