Reading through some earlier posts, I can't believe anyone would seriously advise a 14" barrel, or any barrel shorter than 26" for a general, all 'round shotgun. If you want to look cool while blowing up milk jugs with slugs, by all means buy a "tactical" shotgun. Real wingshooters have realized long ago that "standard" or longer barrels smooth the swing and improve hits. As for 3-1/2" shells, they are a solution to a problem that is so rare that it would be foolish to buy a shotgun specialized for long range and large steel shot, then expect it to balance and perform adequately for upland birds or clay targets. I shoot nearly all my geese with 2-3/4" steel, and also rarely with 3" steel or a premium non-toxic load.
My advice? a 12 ga 3" Remington, Browning or similar good quality pump with 28" barrel with screw-in chokes. An interchangeable slug barrel is a nice option. Many thousands of shooters would agree.