Most lenders will offer two options:1: 20% down and 20 yr amortization and 10 yr term.2. 25% down and 25 yr amortization and 10 year term.Rates will vary by region, lender, and relationship with your lender.  

Take a look at the find a lender tab or work with a broker who can quote you multiple options from a wide variety of lenders! 

Now a permanent buy down option (where they just pay points in a traditional manner) can solve some minor DTI issues.  

What are my options and potential workarounds?

You could even offer a lease option for when they're back on their feet... get creative and generous!

I would agree with @Michael Smythe - the only way a seller comes around to a sub to transaction is when they have no other options or are uninformed.

Ideally if we played the cards right we would have option to take some of the init you do  Equity out after adding value.Thanks for the help!

We may have some secured options on SFR flips in the $200K range! 

Keep your options open and decide what works best for you and, just as importantly, what strategy your particularly property will fit.

We have been discussing options on how to move forward.