Eddie, "vertically configured" simply meant with the drivers arranged vertically rather than horizontally and applies to all sizes of speakers. I was thinking of M22s, either the bookshelves mounted on the wall or the on-wall/in-wall version.
Looking at your proposed setup, with the TV high above the fireplace, and the speakers presumably at the same level, a different thought immediately comes to mind: use the right wall rather than the fireplace wall. Unless there's some problem with that wall that isn't shown on the diagram, the TV and speakers could all be mounted at a more convenient height for both video and audio. The main couch would of course be about where the smaller one is now.
