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.  

The more I think about it, the more I realize that a Solo 401k is probably not an option for me because I will not have self-employment income. 

@Orane JacobsHouse hacking in San Diego is a smart option even with the expensive real estate market.

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

What are my options and potential workarounds?

Buy a multi-family (MF) property, live in one unit, and rent out the rest.

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!

I'm considering investing in a multi-family home near downtown St.

If you log on to some of the popular sites like furnishedfinder or Airbnb you will see that they have "rent by the room" options.