A nice thing about the Mossbergs is the placement of the safety, easy to work with your fireing thumb. Buckshot spreads out about an inch for every yard of travel, so inside the house you are still looking at a fairly tight pattern. Mossbergs are also available all over and at a good price. You need to see how your shotgun patterns at 1, 3,5,7, 10 and 15 yards with your chosen defensive ammo. I've seen a stock Mossberg with PMC 00 buck shoot almost
as well as the very expensive custom gun and high priced ammo (belonged to the instructor). You may find that your gun "likes" one type of ammo, so try a few brands.
A high visability follower with a "bump" you can feel in the dark is a good idea as well a some method to have ammo on the gun. 2 important Shotgun Rules, work the slide after each shot and shoot 1, load 1.

Dave