While on the subject, any tips for ensuring (as best as possible) that I am able to secure a tenant(s) into the other units as soon after closing as possible?

Consider diversifying your portfolio by exploring various types of properties, such as single-family homes, multi-unit buildings, commercial properties, or vacation rentals.

The guy that owned it had like 20 other similar units on the side of the same mountain.

Usually, 20 to 30 units is the tipping point for self-management, so you might want to keep expanding your doors until you feel the benefits of that cash flow (as well as the pain of the management).  

If you plan to live in a unit, you can use FHA or conventional financing.

If you choose to buy another primary you can use Fannie Mae and only need 5% even for a 2-4 unit.

Even in my core markets like Berwyn, where we lease all the time, I still talk to have a dozen friends who own and rent out units to get their sense of where the market is when I am getting ready to list. 

'mid-term' and it's just an aspect of renting a unit this way that you'll have to deal with.

In under 10 years I've bought over 2000 units (and own about 1000, due to selling some).  

I'm interested primarily in MF investing, I would like to skip residential MF and go right to commercial and start with about 10 - 30 unit bldng.