I thought builders/contractors etc used other stores outside of the "mainstream." 

The purpose of this test is to ensure that the property generates enough rental income to cover the property's mortgage payment, including principal, interest, taxes, insurance, and homeowners association dues (if applicable).Key Points of the FHA Self-Sufficiency Test:Applicable Properties: The self-sufficiency test applies only to 3- or 4-unit properties being purchased or refinanced with an FHA loan.

Also if you're in Zillow, another strategy you can try is to click the rent feature and click on properties for rent in the areas you're interested in and look at number of views + applications.

The best deal I made (for me) was an 75% Interest in a small property rented to a convenience store.  

I'm using TransUnion through Apartments.com applications. 

They didn't have to drive to the store?

And most importantly they can help you vet out any potential lease applicant so you as the owner do not make a haste decision and lease the home to someone who may not be best tenant prospect

Probably lost a few applicants by demanding the higher security deposit, but it works for us. 

I know of an investor who bought one of these, use it for a few days, and then returned it to the bigbox store once the HVAC was fixed.

MANY MANY scams going on to collect application fees doing exactly that.