A four unit can never generate enough revenue to get a professional management company (neither can my 20 unit honestly), so you are stuck with what you are seeing. 

I've discovered that:They only work with industrial and/or retail (and seem curious/surprised why I'm investigating apartments)They are the listing agents for properties in the area (it is a sellers market where I live).Being a first time investor, I'd like to have a trusted professional in my corner; using a listing agent (at least to me) represents a conflict of interest.Should I be cold calling firms outside of my immediate locale, such as major cities nearby (or national)? 

My experience is in professional property management, at A+/luxury caliber apartment buildings where expectations are high.

You can even do some of this yourself, but you probably will miss a lot of things if you don't have a professional assisting you.Best of luck!

The seller produces a document showing there is no leak (i think by a professional).

Make sure you talk to your tax professional. 

Smaller properties are more stable in that people stay longer (traveling professionals is who you should be marketing to), they are less seasonal and maintain rates year-round, and even if they do get trashed or something gets stolen its a lot smaller recovery cost.

These are professionals with additional training and a stricter code of ethics.

The biggest point to understand is that you can build a professional team in any city. 

There is no shortage of professionals here that have been exactly where you are.