Don,
If you have custom fluoride trays you want a gel fluoride. The brand name doesn't matter as long as ; "for daily use you use a 0.05 concentration of a neutral sodium fluoride gel and for weekly use you use a concentration of a 0.025 neutral sodium fluoride gel."
Ask your pharmacist if they don't stock one, they can get it and if it's not available over the counter get a prescription from one of your docs.
I hope this is useful.
Cheers,
Mike