Sadly, it seems that cash flow on long term rentals with 20% down just does not exist in most desirable locations.

We found an opportunity to purchase a huge SFR with two kitchens located next to a commercial zone which was previously used as a sober living facility.

I would study the listings from the top performing rentals in your area to see how they are overcoming any challenges with location.

In those days it was possible to locate and tie up a “killer” deal, and close the transaction with absolutely zero of the investors own money.

For long-term growth, consider newer single-family homes in high-appreciation suburbs or well-located small multi-family properties.

Also make sure to build on a property located in a desirable location with larger pop density and if holding for rentals, charge median rent for that market as lenders want to see a bigger pool of buyers/renters available to occupy/sell. 

It's going to be location specific.

While I am normally in the do-not-sell camp, in this case it might just sell and buy at the new location.

The type of the neighborhoods where his properties were located didn't fit in with my plan but he did well and the purchase costs were low.

What location?