RE: Double footstraps-still available?
What kind of board is it for? Some of the starboard carves can be converted to single strap in the back by using the front fin screw as the back attachment for the strap. I did it on my carve 99. You just need a longer screw and a spacer to make the fin-screw hole flush with the deck of the board. (I used a round piece of wood with a hole drilled through it.) Good luck finding what you need.
I tried a diagonal strap in the back but didn't like it.