I found 'doodads' for my Benelli, and they weren't too expensive. Got a Nordic Components +2 mag extension with rail equipped barrel clamp, a Mesa Tactical integral picatinny rail and shell holder, a Xenon flashlight, and a Burris Fastfire II dot scope. Thinking of swapping out the Comfort Tech stock for a Mesa Tactical Urbino Tactical Stock. I like the pistol grip and the price is good.If you want to leave it stock, get the benelli.
If you want to hang doodads on it/"customize" it, get the 870.