Exit strategies for creative financing

[Ian Dale Ibrado]

Currently in talks with a seller considering a seller finance deal.  His situation is that he would like to getting paid long term. Income coming in for 20 to 30years from interest plus principal but he is around 60years old and doesnt want to be a landlord anymore and deal with tenants.  Basically he doesnt want a money in the bank, he wants money making more money.  I just want to come up with an exit strategy in case my current situation changes. I was thinking of getting balloon payment in the 10, 15 or 20 year mark depending on situation.

would love to hear what others think

Thanks