When I moved back to Michigan and started hunting deer, I found out that the lower half of the lower peninsula is shotgun/muzzleloader/handgun. At that time, the only shotgun I had was a Winchester 140 semi-auto that I used for years while bird and small game hunting and shooting informal trap. It had a 28" barrel with Winchokes. I found a scope mount for it and put on a fixed 3x Weaver, put the Improved choke in it and took a half dozen types of slugs to the range. I found that Brenneke's shot nice enough, around 1.5"-2" at 50 yards with this combo. Now, this isn't as good as a friend's 870 3/4" at 50 yards with the rifle sights, but it's acceptable, so I never thought about buying another barrel or another shotgun. Sure, the barrel is 2"-4" longer than a regular slug barrel, but I've never found that to be a problem. This gun only shoots 2 3/4" shells but deer have never noticed that it isn't a 3" or 3.5" magnum.
I guess what I'm trying to say is that just about anything could possibly work. A friend has a Remington 1100 with a 28" modified barrel with a bead sight on it. He threw a scope on the gun and uses it very sucessfully. Shop around and consider the possibilities but most important, fire different loads to see which the gun will like best and then stick with that load. Shotguns seem more finicky than rifles as to load preference.