hi tom,
i got mine from
www.ryderfleetproducts.com
i buy the ones with removeable sockets, not sealed.
that way you can use the bulb that comes or put an led in. you have to buy the socket/pigtail separatly.
they are not stocked but come in a few weeks.
Truck-Lite Back-up light rectangular clear - 07096C
Truck-Lite Socket Stop/Tail/Turn - 95415
tom