Not familiar with much like that. Dainese has a pretty extensive range of safety gear, maybe look them up?
I would think protection requires more support from surrounding areas like armored chest and shoulders, which is why I bet you don't see just shoulder/clavicle protection too much. If at all? I think they make one for hockey players, but it looks sort of restrictive.
Sadly sometimes, no matter what you do, something is going to break, riding IS dangerous.

A very experienced, well rounded and skilled buddy here just broke his in a "freak" accident: pedal caught a rock as speed on a familiar trail, but still - down he went.