There is another Applescript method to get around the security settings, and it returns two lists. First is a list of all System Fonts (all styles) and the second is all the Font Families (which is exactly the same as returned in the method previously described). It uses the atsutil in a "do shell script" command and pushes the result to the clipboard which then can be pasted into any field. The Applescript is only one line. FileMaker Pro script looks like this...

Perform Applescript [ "do shell script "atsutil fonts -list | pbcopy"" ]
Paste [ Select ; Fonts::FontInputText ]

The text returned looks like this and you can do whatever you need to style text

System Fonts:
    AcademyEngravedLetPlain
    Agenda-Black
    AlBayan
    AlBayan-Bold
    AlNile
    AlNile-Bold
    AlTarikh
        ...
System Families:
    Academy Engraved LET
    Agenda
    Al Bayan
    Al Nile
    Al Tarikh
        ...