I'm looking at investing in a short term rental in Jacksonville, my budget is fairly modest though, up to $300k so I'm not looking to do a high-end STR.

Long story short, he ended up buying a worthless piece of land. 

If that time is relatively short, then a refi might make sense.

Just suck it up in the short term and reap the benefits in the future.

Also consider short term month-month leases on airbnb, renting individual rooms, month to month leases, just to get the cashflow energy flowing again.  

He appreciated my passion and wanted to help me get to where he is in short time.

One more reason why long-distance management is a bad idea.

I will do my homework on long distance REI (even tho the markets are 1-2 hours away), but have a couple questions- What are some of your key metrics/signs you use when identifying a new market?

or Do I turn the Fl house into a short term rental property and look to finance the 6 cabins?

There's some connection you have to this person with money who is looking to invest it short term and collect an x% return.