IMO you want something to carry around maverick 88 foldover stock is as light as you can get.
You want a CQB weapon 870 with a speedfeed or a knox is the best way to handle recoil (steel reciever, heavier barrel/tube makes it tamer to shoot, but obviously heavier to pack, mossber is alumimum only time this matters is weight, and on the mossberg take your time installing a side saddle, over torquing the screws is a concern, but no issues in use)
I have a 870 set up for skeet. custom 3.0 lb adjustable trigger it is awesome, got it for 180, trigger for 75 bucks. still has factory grease on it.
I have a maverick 88 for carrying around Mine has a vent rib barrel its easier for me to aim, I have no idea why. one point sling and its golden. Choate stock, I definitely like it. maverick 88 also has the trigger safety (necessary IMO if you wnat a pistol grip) Oh got the smith for $40 to file down the bolt a bit, it cycles smoother than any other pump I've ever seen. (people call it ridiculous but it can be pumped silently in an emergency situation but can still rack if trying to frighten a mob so you know who to shoot, the only one not running duh!) Oh mossberg shell lifters stay in the up position unless cycling so you don't have to worry about cutting your thumb off loading, couple times dove hunting I got my thumb stuck in a magazine tube of an 870, that wouldn't do me any good in a fight.
If your a speedfeed stock guy, mossberg 500 might be for you.
Pistol grip without a foldover your soo far beyond help I don't know what to say.
So basically what I view as acceptable stocks
Knox with recoil compensation (pistol grip/buttstock combo)
speedfeed (rifle stock or with pistol grip)
foldovers (NO ATI NO ATI, pretty much any of them are good, each have their own advantages andn disadvantages, I chose choate due to length, blackhawk looks good too) only to be used if you want low weight/compact transport reasons, they are simply not as good as a fixed stock.
Barrel set ups: Vent rib cut down (I Like, I'm weird) barrel shroud often done with ghost ring on a 18.6 bead. you can get a picatanny rail on top of a remington reciever, or an attachment through the pins for the mossbers due to aluminum reciever(have seen a red dot on the reciever of a mossber, but I wouldn't do it). You can get a fiber optic turkey style set of sights or a tritium/tritium fiber optic sight
another option is a maverick 88 with the 20" barrel and its 7+1 ammunition, if you don't care about weight, and want more rounds its a very viable option. You can get a tube extension on an 870 but remington doesn't think you deserve it so you can't get manufacturer parts.
All I'm saying is think about what you want. Want a sling? 1 point, or a bandoleer sling (heavy but nice)
Do you want a light? if so figure it out how you wannt to attach it before buying a new forestock, many are intertwined.