Need help structuring deal

[Jon Blackburn]

Hi Folks, I need some help please in how best to structure a deal (never done this before). Here are details:

• $50,000 (list price) tri-plex with two units occupied. Third (larger) unit needs $15k in rehab. ARV should be $80,000.
• $850 in monthly rent, will go up to $1,450 after.

This is well beyond 2% rule, but I may struggle to get conventional lending if putting 25% down or negotiating a price below $50k. The seller seems open to getting creative (e.g. seller financing). He has roughly $31k left on the mortgage. So how would you structure this deal to pull off the steps?

Should I pay him $31k cash to get his mortgage paid off, and then have him seller finance the rest so I can use my remaining cash for rehab? Then refinance the property afterward?

Should I try to use hard lending for the rehab? 

Would you go about it a different way?