In regards to licensing for (FJ) St. Barts. I have operated from FJ, FG and FS. These french posessions fall under the CEPT agreement. The three of them recognize the U.S. participation in the CEPT. An example for you signing your call would be FJ/AH8DX. Take your U.S. license and a copy of the FCC Public Notice (DA 99-2344). This document is printed in English, French and German.
Secondly, make a master list of your equipment and include Manuf. of Equipment, serial numbers, and description. I would not include dollar amounts of each item in case customs wants to look at your list. Fortunately customs is a piece of cake. You basically just claim your luggage and you are finished.
Gud Dx es GL, Craig AH8DX