While Orlando is a huge STR market, I'm also aware that it is currently a tough and saturated market. 

I still haven't gotten the link for the new portal so I can't see the lease for the tenant and I haven't seen any money come in for August rent (PM get full first months rent so I wouldn't have gotten anything for July).In June my PM found me an off market deal and his contracting business is doing the rehab (which he's done for me before).

The market rent needs to be around $1,800 per side and no more than 2k a month (depending of finshes) I'm having a hard time getting someone to nail down a price on construction cost.

I live in a cheaper market with a lot of sub-75k properties.

They literally wrote the book on midterm rentals and cover how to analyze markets.

I came across a podcast that talked about the NACA program but didn't go into full detail.

Yes, Builders have a lot of margin that they are working with typically because they set the market and manipulate the home prices.

With the economy and market as they are, should I continue aggressively paying down the HELOC to potentially borrow against again or should I just pay the Interest Only (IO) payments and seek other funding at the current day higher interest rates?

It is not on the market but I have an investor who is interested in purchasing it. 

And, residents need employment; otherwise, units are full but some can't pay.In many markets, there's a pretty large jump from C to D class...and in most markets, D class takes very hands on, local management.