RE: which 3 1/2 inch shotgun to get
The mossberg and 870 are great choices. A few claims have came out against the 870 supermag saying it didn't chamber all the way and blew the reciever out. If you do a search last year on it, you will find it here. But I am sure remington has remedied the issue if there was any. Especially one that could hit the wallet. I am thinking of putting together a turkey only gun. No need for a semi for turkey. Keep the semi for pheasents and ducks, maybe squrrels.
I would like to have a scoped shotgun I could pattern out to 50 yards with hevishot. I have seen guns very 50 yard capable.