Forget the bling and keep it practical, BA/UU/R.
The Sidesaddle made for 870s will fit it, if yours has the long forearm that covers part of the loading port when the action is open you'll either have to get the 4-shot version, or swap out the forearm to a short LE length 870 version or trim the sporting length forearm to about 7" or so overall to use the 6-round Sidesaddle.
You should have sling swivels already, stick on a decent QD carrying strap.
With some magazine tube available out in front of the forearm, there's room for a Streamlight shotgun magazine tube light rail like the 69903. That and a good QD weapon light like the TLR-3 will get you a white light on board.
The existing stock is good, if it fits you. It can be shortened like a wood stock, as the sidewalls are good and thick and the heel/toe have a little extra beef too.
Main thing is to build skill with it...
lpl