Nick,
Are you sayig a Sinar / Horseman type board will fit directly without an adaptor?
If that is the case, then the only other consideration beyond what you mentioned in your latest post, is what advantage might there be to you to stay with one standard board, should you acquire a different camera.
All my 4x5 lenses are on Technika type boards. For my 8x10 field camera, I have an adapter board to use the lenses that will mount on a Technika board (including my longer 4x5 lenses that cover the 8x10 format), but for the two larger ones (420mm & 600mm) that will not, they are mounted on 6x6 boards that fit directly on the camera w/o an adapter.
Len