Based on email / phone communication with the county officials, it appears there are no properties affected by sinkholes in their database.
We investigated this further with sinkhole data from Florida Department of Environment Protection (DEP) and Plotscan.com. Although there are several sinkholes found from both data source, it is likely most of them occurred at non-residential area or off properties.
UPDATE 3/15/2018: We now have DEP data for these two counties. Properties on these maps are likely not indicated as sinkhole properties in the county websites.
Manatee County Sinkhole Data from DEP and Plotscan
Sarasota County Sinkhole Data from DEP and Plotscan