Pettifogger, I'm trying to understand what you mean by "The Supreme isn't a coach gun."
Both the 31400 and the 31483 come with 20 " barrels fro the factory. No cutting needed.
The biggest difference between them from a functional point of view is the factory installation of a rubber butt pad. There is no "drop-in" replacement pad available for the Stoeger, so $50 buys both the pad and the avoidance of grinding a generic one to fit.
The more expensive model has chokes as well, but they are bored into the barrel rather than replaceable, and they are not identical in the left verses the right. By getting the $50 more expensive version, you not only get the rubber pad, but also the option to mess with the chokes and make them both the same if you wish to as an added bonus. You can also choose to ignore them if you wish.
The stainless receiver option is also an added bonus.
On top of that, the wood is a bit better on the $50 more expensive "Supreme" model.
You get a lot for only $50 more.
Rick