Koenig is the common mfgr I've seen. Cam just got one, it's attached to a J10 or J20.
Seem to recall that Pierce offers a PTO version. Might search their page.
Ruben @ Vta 4x4 bought my Koenig for a customer. They didn't need all of it though, but I can't recall what they did need. Might see if any of it is available.