I have a few suggestions. Build an exact prototype out of wood, and be ready to modify it based on what you learn by having a number of shooters try it out. I think that it is a good idea to use an adjustable stool when the prototype is being tested, and to be sure to have shooters of a wide range of heights and builds participate. If the members of a club have not had much experience with good benches, and if their current benches have some wobble, they may not really understand that benches that do not move when leaned on are possible to build, and if they do not shoot benchrest, they may not understand the importance of benches having this characteristic. Of course, never go with a design that has seating attached to the bench, or that is unable to be moved.