However some of the "easy parts" of residential change like financing and the term of the note.

If you're wholesaling residential properties, keep in mind that most property owners will also be speaking with and meeting local investors and realtors.

I'm interested in multi-family investment and want to buy a residential multi-family (2-4 units) to live in one unit.Ideally in Montgomery County as I live in Rockville (or PG county/Baltimore)

Interesting that this seems to cover all property zoned residential, with no apparent carve out for a transaction of residential property between two investors.  

DTI ratios are generally used in consumer/residential (aka primary) mortgages when the property is in your personal name.

I'm a Project Manager at an Architectural Firm specializing in Custom High-End Homes.  I started my Real Estate Investment Journey in 2016, have flipped four homes since then, and own one rental.  I am looking to get ...

@Blake McWilliams This is a most challenging problem with both residential and commercial investors.

We are looking to buy a residential, multi family unit.

I would start speaking with residential / commercial agents and property management companies close by and get a feeling if something closer by will meet your criteria.

There aren’t many residential development companies operating at this level, which reduces competition and risk.