Very VERY small commercial deal with seller financing

[Kathleen DeNault-Ridge]

I am considering the purchase of a small commercial mixed-use property.  It is a building with two current multi-year leases (post office, yoga studio...no history of lengthy vacancies), and a very small owner-occupied launderette (coin-op).  The long time owners want to retire.  The property cash flows.  The owners are willing to seller finance.  I'm not sure how to structure the deal.  I spoke with a local commercial banker and he recommends:

bank financing the purchase price for 20 years (5 years fixed and floating after that)

20% down

because sellers are motivated and have agreed to seller finance: he recommended having the sellers carry back a second mortgage which used to supplement our equity to come up with the down payment.

I have read that when seller financing the goal is get the seller to finance between 40-60% of the price.  In previous discussions with the seller, they agreed to seller-finance almost 70% of the deal (they just want their existing small mortgage satisfied so they can retire). Should the deal have a higher percentage of seller financing or is the seller financing a portion of the down payment a reasonable approach (the bank seemed to like that approach more)?   What kind of terms should be used with the seller financing portion?  How does this all work at closing (a double closing??) and how is that coordinated?

Thanks,

Kathleen