For example, I expect to see the 870 in 12ga a lot.
The vast majority of defense shotguns are either semi-automatics or pump-action. In a real life defense situation I don't care about the finish on my muzzle. Shorter persons or persons with shorter arms generally prefer stocks with shorter pulls. Squirrels, birds, and you don't want to destroy the meat. Single-shot and double-barrel shotguns will do in a pinch for defense, but it's always nice to have additional capacity in one's defense gun. Therefore, from a versatility standpoint, your defense gun should be a smoothbore.
But lets say that the shotguns you try at the store don't fit. My opinion would be to make either the rifle or the pistol a . For example, I expect to see the 870 in 12ga a lot. Mossberg 500, nine shots, bayonet, ghost ring sight. Taller individuals or individuals with longer arms generally prefer stocks with longer pulls.
Most plain Jane shotguns will come equipped with a front bead as the front sight. This unit replaces your slide or fore-end with a compact unit sporting an integral light module. It used to be that eight and four gauge shotguns would be used to take down elephants in Africa.