I would think a lot depends on just what in particular you wish to do. What type of geographical set up where ever you live.. If like here in New England, lot's of rock, granite, stone, rock outcroppings and more rock and stone.. Some who stay in the city type environment like the 39 over the 48. Most out in the "territories" such as where I am at, use the 48. Tell us some more about where you live, are you picking up pallets of stone and brick, or just removing ground,,, Giving us a little more detail in what you would like to do would help get you quicker answers,