There are hybrid loans that may look in part at the borrower and the property and make an assessment on whether or not to write the loan.The best way to find the loan is to just start calling banks, brokers and other non-conventional lenders.  

Maybe you can borrow against for down payment and pay back after closing with unsecured line or when property sells?

Unfortunately most tenants assume their landlord is a lending institution and do not hesitate to borrow their landlords rent money.

According to HUD 4155.1, Chapter 2 Section B, A non-occupying borrower transaction involves two or more borrowers where one or more of the borrower(s) will not occupy the property as his/her primary residence.

Aaaaaaaaaand they would shoot you down, as unsecured borrowed funds cannot be down payment or cash to close.

IMO borrower paid monthly PMI (the "standard" or "normal") almost always makes the most sense. 

Can you borrow on your retirement?  

We are not interested in borrowing against it.

Lastly, for a Letter of Intent from a lender, there are two pieces to the equation; the strength of the borrower and the strength of the commercial property. 

Common pitfalls are poor underwriting, poor risk assessment, being over zealous, sacrificing prudent lending practice to gain an edge on competitors, no take-out for you loans, lack of available capital, over-promising borrowers and not delivering, improper loan documents or the absence of material docs.