Every thing works out to be a matter of scale. You will be slimming down any percarve on the market to suit your 3/4 in barrel. The nice thing is if you build from the slab you can start with a 1 1/2 in thick blank if you are building a later period gun, say post 1800. Also if you have a interest in building one of the "marginal" stock designs for shooting comfort your barrel and caliber choice is the way to go. Upper Susquehanna guns come to mind, Or a super skinny Allentown, Hmmmm