More important at this point, is to meet as many lenders and other investors as you can, large and small.

He also tells me the large property management company 30 minutes away sticks with gas for all SFH rentals.

Im going to start looking at the for rent ads to see if there are any landlords that are looking for a way out.

Part of this limitation is that there are 1300 Section 8 vouchers floating around in my county; a very large number. 

We debated about keeping it as a rental, flipping the existing house, or adding on.

On a more personal note, I was given plenty of opportunities growing up, which I think a large portion of my generation takes for granted.

Because we did the majority of the work ourselves, the total rehab budget wound up being around $30,000 (which includes adding a deck, fencing in the huge back yard, fixing the driveway and adding a paver front walkway.)

Sounds like you have added close to $100k of value, added $1,000 a month of tax smart cashflow to your bottom line, improved your personal quality of life, reduced your company's business expenses, and still have more upside.  

The property is comprised of four 2b/1ba units in the South Dallas-Fair Park neighborhood and is right across the street from a large industrial plant.

It's ordinary income, added to your salty so you can look it up on a current taxes schedule, plus add 15.3% for the SS/med self employment.