One big advantage of buying a Remington 870 model IS it's versatility.
Virtually ALL Remington barrels will interchange with and fit your gun. As above, only the Marine model has a nickel plated barrel, but the barrels will fit and function perfectly.
If you invest in a longer barrel with screw-in chokes, (which is the standard for MOST Remington replacement barrels), you can shoot almost any game or sport.
By switching the screw-in choke you can shoot anything from close range quail to geese, trap and skeet, squirrels and pheasant to turkeys.
Although the bright nickel finish may not be the best option for hunting game, or shooting clays, the gun itself will "do it all".
Switching from the home defense configuration of you Marine model to a sporting model is easy, but does require a few spare parts.
You will need:
A new, longer barrel with screw-in choke system.
Extra choke tubes in whatever choke is recommended for whatever you're planning to shoot. Spare tubes are fairly cheap.
A shorter magazine spring. With the extension off, the longer spring won't work, so buy a new Remington factory standard length spring.
A new magazine cap. This replaces the extension and holds the barrel on. Be SURE to buy the older style cap, NOT the newer Express cap which won't work.
A new magazine spring retainer. This is a cup shaped spring washer that retains the magazine spring in the tube.
If hunting some game like ducks, Federal law requires you to plug the magazine so it only holds 3 rounds.
You can buy a plug or make one from a piece of wooden dowel rod.
If you shop around gun shops, you can often buy the mag spring, mag cap, and spring retainer cheap, since many shops have "take off's" in their spare parts bins.
So, with the original 18" barrel, and a longer screw-in choke barrel, you can use your gun for virtually ANY shotgun purpose.