I have about 60k cash that I could put down, but how does a person get a loan for the remaining balance?  

Your friend must have an NAID # and if they do not know what that is....well it will take them 2 months to get oneIf you want to remain friends.......find another agent

We would house-hack and use one of the units as our home base (since during travel therapy you have to have a permanent residence to return to for tax purposes) and rent out the remaining units to pay for the other expenses.

Once the home has a C of O, we rent to own them at $725.00 per month ($340 goes to lot rent and the remaining $380 is their home payment).

Is you wife clearly the heir.. is there a will, does your wife have a copy,,Or... what if one parent dies and then poof the remaining one gets remarried,,, what happens then..  

Unfortunately for them they remained stagnant.   

Installed a $100,000 dock a couple years ago with all the proper permits Zestimate has not changed in 3 years by more than a couple percent Anyway to let Zillow know in hopes they will increase the zestimate Remains the same as a neighboring house with no dock. 

if it is aggressive then it will remain so. 

Like to know if I should buy another investment property or pay off the 2 remaining and my home.

Once you increase your budget, go back and remain to the ones you already touched once.