Those Kodak holders are about the best ones going in 9x12, too. They don't need film inserts; they have a spring-loaded pressure plate that auto-adjusts for sheet film or plates.
Also, the shutter is removable as a unit, so reusing the lens on another camera should be easy. It's the same unit that I made into a tilt-shift EOS lens using hardware-store parts.
(You know, Perry, 9x12 contact prints fit nicely in a standard 3.5x5 frame. What's an enlarger? :-)