I imagine for something really simple like a SD-Roth with LLC/checkbook would be far less initially and annual payments vs more complex structures where x transactions/yr occur. 

In fact, there's evidence that this is already occurring.

What makes a self-directed IRA custodian different is that they are not purely connected to the public exchanges and limited to investing in stocks, bonds and funds, but rather have the staff training and paperwork to document the IRA's investment in the more individualized transactions that occur when investing in real estate, notes and other non-traditional assets.

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

Might do you more harm than good."

Now if that duplex is located in a condo association (which does occur in mixed use condo associations in Florida) then it might be possible. 

Our Saratoga meetup occurs every third Tuesday of the month at Jacob and Anthonys in Saratoga at 7pm.

We don’t know any PMCs to recommend in the area mentioned, but since selecting the wrong PMC is usually more harmful than selecting a bad tenant, you might want to read our series about “How to Screen a PMC Better than a Tenant”:https://www.biggerpockets.com/member-blogs/3094/91877-how-to-screen-a-pmc-better-than-a-tenant-part-1-services-and-processesWe recommend you get management contracts from several PMCs and compare the services they cover and, more importantly, what they each DO NOT cover.

Do you know how long ago the fire occurred? 

Mortgage companies typically will not allow a wrap loan for an Owner finance deal to occur because of the risks involved to them.