Try to pull vacancy data for your metro area or even zip code if possible—the more specific and granular, the better.

Connect with top real estate producers in the zip code and notify them about your listing and see if you van make a deal.

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

For example in Nashville a NOO STR eligible zoning code will appraise for WAY more than the exact same house next door if it does not allow NOO STR.

Find the ARV of a particular type of home in a particular neighborhood/block/zip code (whatever makes sense for your area) and create an auto email so you get an alert when something is listed at 60% of that ARV.

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

However, the best method I used to determine my CPA (or at least where I ended up) was just picking up the phone, calling places, asking a list of questions that were important to me, and scheduling a meeting if I decided they were worth a deeper conversation.Once the meeting came around (whether in-person or video chat), I asked very specific questions about my intentions of using the tax code to my advantage through REI and essentially 'tested' their readiness to lead a client of my nature. 

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

FYI Section 8 has limits on increases and has rent amount standards for the size of the unit and zip code.

When you have to follow code and have insulation wiring and plumbing all a certain way it makes it much easier to build a box designed around your plans, than plan a build around a bunch of small cheap boxes.