I need help finding the mortgage holder for a particular property; any suggestions?

You can search property tax records at your local county office or even on-line in some jurisdictions to find that information. Where do you live?

I live in Miami Florida, the web site, (MiamiDade.Gov), does not list the current lender

You will have to go in person, or pay a para legal search company to physcially do the search

Click on Property Search link at the left side of that site, it will let you look up a parcel of land and give you the info you are looking for.

Are you looking for the mortgage holder or the lender as you refer to both? This will tell you the Owner, not the lender.