I've got a Remington 870 Police Magnum (walnut furniture and parkerized), factory 2-shot extension, Streamlight TLR-1 flashlight, M1 carbine-type OD cotton sling, a detachable nylon 6-shot side saddle from S&J Hardware, as well as their jumbo head safety. It's my home defense gun, but I sure would love to be able to just have fun with it plinking. I had a hell of a lot of fun a few months back in a steel plate competition on Long Island, can't wait for the next one.
Picture was taken before the Streamlight was added.
That is one of the nicest looking shotguns I have seen...
Mine had the +2 extension from the factory, I took it off, it handles much nicer for me, and I added a Knoxx non-recoil reducing stock, so my wife and kids can shoot it comfortably. My only "must recommend" item I have added to it, though, is the Wilson Combat/Scattergun Tech bighead safety. With the awkward spot the safety is in (I know, opinion, but it is true for me) it makes it easier to knock the safety off when needed.