However, if they can adopt most/all your properties I think you also established a stagged approach to increasing their rent.

@Nicholas A. your shotgun approach has a high probability of getting the exact quality you put into it.95%+ of real estate agent, many of them posting they are "investor-friendly", only know how to deal with owner-occupied transactions. 

Since your lender requires prior experience building and selling/refinancing a single-family residence (SFR) on your own property, you may need to adjust your approach.

Your location, your list, your approach, market conditions, time of year etc.The only thing I can tell you with 100% certainty is you'll need to SMS a lot more people than you will need to cold call.

What are your biggest challenges to achieving that?

Challenges?

Often the best risk, hassle and tax-free approach is to pay down debt.If you have a car note, credit cards, etc pay those off first. 

It will be an identical home to the one I’m currently building, and I expect to need no more than $160K in financing.I’m not looking to overextend myself by taking on too much debt, but I want to make sure I’m approaching this in the right way. 

This does pose a challenge since that real estate is a lot more expensive than if you go more west and south.

By doing this approach you are not competing with the Millions of other investors in SFH or MFH.