I am half way through a self build of a 5x4 camera and have been looking at various videos on YouTube of cameras being un-folded to get some idea of the front mechanism I want to use. The Wista mechanism looks good to me and is probably what I will use. The Chamonix certainly has its merits though, particularly in its simplicity.
I think I must have sketched out about fifty different ideas on this mechanism. I must make a decision soon and make a mock up to test that it all fits together when folded up.