wxashcra,
We manufacture drum brakes and the linear brake can also operate on a disk (or partial disk for 90 degrees operation), so depending on your system's mech. design, inertia, stop time, etc., we may have a solution that could work for you. You would however, have to incorporate a way to...
I am a manufacturer of Linear Brakes that have a force capacity of up to 5500 Lbs., however it is a spring set/air release actuation so it may be more involved than what you are looking for as with the inertia activated system. Primarily used for machinery rather than a free hanging load so...