What is the difference between the Nova and the SuperNova, I have been reading that the SuperNova has a Confort tech pad to reduce kick, but I also read that the SuperNova is capable of having different stocks put on it. Is this true? I really want to be able to switch between longer barrels and pistol grips to change it from a hunting gun to a tactical gun at will. I know it can come with no pistol grip or with a pistol grip, but im wondering if you can change it yourself after you buy it. Also, can you put JUST a pistol grip on it with no butt?