Shoe mount to boom pole
 

Does anyone know who makes an appropriate adaptor to mount this camera shock mount K-Tek | Camera Shoemounting Shockmount | K-CAM-SSM | B&H Photo on a boompole. I've seen it done with 2 adaptors, (5/8" to 1/4" then 1/4" to cold shoe mount) but I haven't seen a one piece solution.

I haven't personally seen a single-piece adapter to recommend but I have put together many combo's over the years for all types of mounts and situations. Hopefully a suggestion will come in that's just what you need. It's the female cold shoe part you need and that's the least frequently seen adapter part.
It is important to have an angle adjustment for a boom-mounted mic, so I would include that in your plan since this shoe mount is rigid.

For information to other people reading this thread about threads for the future:
A regular US mic stand is 5/8"-27.
A boom pole and large tripod is 3/8"-16.
A small tripod (and other misc. use) thread is 1/4"-20.

Camera stores are often the best local source for 3/8, cold shoe and 1/4 adapters.
Musical instrument stores for 5/8 adapters.