I wouldn't take more than 2" off any of the three MRB boats: Honky Dory, Beavertail or Buffalo Boat.

For those who accasionally like to run big water, choose the Honky Dory and leave it the way it is. If your focus is mainly day-trip fishing guiding, choose the Beavertail, or build a Honky Dory with perhaps 2" rocker shaved off. You might want to widen the transom by 2" too. If you do widen the transom you will probably have to move the rear-most temporary rib a little closer to the transom, in order to maintain a smoothly curving chine. This is not rocket science. Just play with it until it looks right.