I also planned to hold this property for long time.

I also suggest you post your listing to "Short Term Rental Listing Advice" on Facebook and let them give you more feedback as well.  

Can anyone shed some light on what kind of down payment, terms and qualification requirements we would typically be looking at for an SBA or low down commercial loan?

Investment Info:Single-family residence buy & hold investment.

Also, I work with a lot of long-term RE investors and none of them look at ROI.

Real Estate buy and hold, Crypto, Private Lending, Industrial Syndication?

There are several non-QM options that will work around that but with "hits" to the loan terms.  

My long-term goal is to own 20 units, and I’m trying to figure out the best strategy to keep growing.Current SituationI've been using my primary residence’s HELOC to finance and renovate my rental properties.

20% down is doable for a lot of lenders, 15% down is available in some cases but will come with horrific terms. 

The attorneys I have worked with when buying a large apartment complex have all recommend one LLC for holding the property and one for managing it.