RE: Which Shotgun
I think the New England Firearms pardner 12ga with full choke would be enough. At our local walmart the gun is priced at about $85.00. Most people will get the more expencive turkey version that shoots a 3-1/2" shell but then they normaly only shoot a 3" shell in it so it' s pretty pointless to spend the extra money.
I wouldn' t get a mossberg. I have one and it' s ok, but when you shoot the slide comes about three quarters of the way which some like, but I don' t.
If you do decide not to get the single shot NEF, I would pick a remington pump. Or a Charles Daily auto. The remington is like a standard to which other shotguns are measured against, and charles daily is comming out with some fair quality products now with good customer sevice.