1) pump shotgun + magazine = retarded
2) avoid anything from Remington made in the past 5 years. it's garbage. there's a reason they're bankrupt.
3) if wanting a mossberg get a 590 in 18" barrel configuration and get yourself a quality side saddle. learn to single load the gun and run it quickly.
4) a quality flashlight mount (like the RS Regulate) and a sling are a plus
5) after all this re-evaluate if you still want a magazine system because the answer will be no
there are many nice mossberg models out there, this one happens to be my favorite. unfortunatley none of the shops seem to carry it. they all have the 590A1s which I find cumbersome. the good thing with mossberg is their QC is pretty good on the shotguns so ordering one is a nonissue. the standard 590 is about 1 lb lighter than a 590A1.
590 7-Shot | O.F. Mossberg & Sons
View: https://www.youtube.com/watch?v=BT-GhcSt3sM