Ritchey used to make them. I had a pair on my road bike. They were perfectly usable and supportive, but a double sided pedal I found easier. Xtremely light though. And beautiful, easily the most beautiful pedal I have seen. I had a look on the big German websites but no luck there.
I used single sides for a couple of years I got fed up constantly having to flip the pedal to clip in (usually at inconvenient moments)so I've gone back to double sided and fitted my single sides pedals to my turbo trainer bike.