This all came off a Remington 1100 build I was doing but went another direction.  

ATI Pistol grip stick fits 870, but more so the 1100 & 11-87 because of the spring tube that runs through the stock.  $40


Quadrail heat shield fits 870, 1100, 11-87, most Remington shotguns I think.  $80

Quick flip adjustable F/R sights - SOLD

Everything together for $100