DM and instructor progression.

[TSandM]

I'd say do your DM course with the agency that has instructors you want to work with. I doubt you are going to travel to Okinawa regularly to help teach classes, right? So doing the class with the agency that's local is going to make it possible for you to do more.

 

[DCBC]

...That is true, I am considering which agency as well. There's really no way to separate it, from the decision process.

Regardless of where you are trained, the Agency you choose will allow/restrict what (and when) you teach a particular subject or skill. For me, this is a crucial factor to which Agencies I affiliate myself with. It really depends on why you are teaching and what you hope to accomplish by doing so. Good luck Mitch!