RE: which shotgun?
Don't go too cheap on an auto. There are some real good inexpensive models. The Stoeger 2000, Traditions ALS 2100, and Verona SX405. They are pretty reliable, well made, light in weight, and versatile. The Traditions ALS 2100 which is based of the Beretta 303 design used to be marketed as the Stoeger Luger until Beretta bought out Stoeger and marketed the 2000.