I knew just from your posts that someone was influencing you for their gain. 

Also, the amount of debt that is added to the deal (a 50% LTV is typical) will influence your return from appreciation.

SFR values can swing pretty wide because there are SFR owners who are not investors influencing the market.

Ma & Pa investor don't know how to work the market (which has volatility, "flash crashes", hacks, hedge fund manipulation,) and plenty of outside influences outside of their control, that limit their growth.

Your area, jurisdiction and the political flavor of your courts influence whether or not an LLC is right for you, so see your attorney.

Abandon the Peurto Rico dream for now and look at more realistic/beginner friendly areas that still sport a large latin influence and strong rentals, like Florida (I've looked a little bit outside Miami..Boca Raton, Tampa, West Palm Beach, etc). 

As to what's best is to be decided by you personally as each individual's situation is different and is influenced by your time commitment/money/tax implications/long term goals. 

It will have nothing to do with the local lender because they don't get to choose the appraiser or influence that at all.

Specifically, I’m interested in understanding the factors influencing land values in this area and any recent trends that may impact the pricing of these lots.

Your Center of Influence list is a better list by far