I'm interested in boat/rv as well and feel there is a need in the local area here as well as Volusia County.

I've reviewed the ADU rules on some of the different city's websites, now I realize how much variance there is just within the county...For example, Santee has a new owner occupancy requirement that will go into effect on any ADU's permitted after 2024 and a strict no STR policy, La Mesa on the other hand seems really ADU friendly.Does anyone here have recommendations on which cities in SD county to avoid and which to explore for ADU's?

You can lookup the tax rate on the county assessor website - Make sure you are looking at or calculating the property tax WITHOUT any exemptions (since you’ll not get any as an investor). 

I do know they have stopped funding in lewis county as they couldn't fund one of mine down there. 

Might even be the same that challenged the sale at the county. 

@Jacob Henry Wirth yes you can do it in Orange County. 

Property is in Sumter county.

My family is planning on moving to Franklin County area (preferably Franklinton/Louisburg) in the coming months.

They're hard to find, but they're in and out of the county building checking on land to build.

The site is for the Law firm that handles all of Harris County's tax lien foreclosures.