How to structure seller financing?

[Yahya Moataz]

I have a Quadplex im looking to buy and until recently was going to secure bridge loan into refinance once rent stabilized. However, after negotiations and more conversations with the seller, he is willing to carry and i got him to consider owner financing! 

QUESTION 

How should I structure this deal creatively? I understand this is definitely way better than the bridge but i dont want to move to fast or over leverage myself not working out the terms. How should this deal look? Purchase is going to be $289,999.

THANK YOU IN ADVANCE BIGGERPOCKETS COMMUNITY!