How much time do you have and what is your investment strategy, fix and filp, BRRRs, STRs, buy-and-hold will require different hunting techniques. 

I didn't fully appreciate all the micro-skills required to buy rental properties, when I first started.

Even though I didn't see it first hand(thank goodness for facetime), I had some trusted boots on the ground that allowed me to feel confident that they understood my requirements and had my best interests in mind. 

Also be careful on the zoning as some areas require a COE and are constantly under city scrutiny.

Many states require hard money lenders to be licensed as well.

Most lenders require you to have 6 month seasoning to do a cash-out, but I do know of an option that cuts the seasoning period down to 3 months.

@Tom ServerAdding it over existing subfloor will require you to undercut all your doors, and cause havoc throughout the unitYou should replace it as it’s mentioned.Depending on the square footage of the unit not sure if 5k will be enough and assume unit is completely empty of personal belongings and has no flooring in the unit over the subfloor

Are you looking at buying/building a private strip and expanding the hangar capacity or would this be an off airport storage requiring wing removal and towing?

Conversely, refinancing preserves your current positive cash flow and requires less hands-on work, but you may not secure the same low interest rate and could diminish the equity available for your next house hack.

If you want letters from previous landlords if they can meet your stated income and credit score requirements then, you also state that up front, exactly what you want.And your realtor and attorney should be helping guide you this way.