And the huge upshot is that I will be there in person living in one unit to ensure stabilization is smooth, and staying local (living 10-15 miles away but probably using it as an office weekly) for years to come.

Building on a lake requires experience with the locale and building regulations.

I'd advise you to either do a few deals in your local market- I don't know where you live, but yes, deals are possible there and people are investing.

After speaking with a local realtor and lender for quite some time to just get some information, they advised me that we are currently in a "buyers market" compared to a "sellers market."

Often times even if its a single family home or a multi with separated utilities there are some utilities provided by local government.

The local paper or county website will have all the info you need for auctions, tax deeds, foreclosures, etc.  

Good group of local folks or are they all coming from Atlanta?

First, establish an online presence and join local groups and orgs to get your name out.

Top local RE broker familiar with STR compliance. 

First, understand the local real estate market, including housing prices, rental yields, property taxes, etc.