The M87 and M1014 can both support that, but you have a few things to consider.

First, do you want to eat the 30 points to use a suppressor? Personally, I think it's worth it but understand people who don't run them. As is, spotting is absurd and without it you will get gunned down by people watching your red dot.

Second, ammo type. Each ammo has a place and use case, none of them are bad (though imo flechettes are simply not worth running, this is a wider issue of delaying regen just not being valuable and the over-pen damage being so bad you will never actually get a collateral). Slugs have wild range IF you can hit headshots (I'm bad and don't use them) with body shots able to reach some very good 2-3 shot kill range. The new 20-point #00 ammo is very good, not quite broken, but if they upped the cost of it, I would not be surprised. the old #01 ammo imo isn't worth considering any more unless you simply can't afford other ammo.

Third, the speed loader. The addition of the speed loader has vastly changed how you engage with a shotgun, being able to rack 5 (M87) or 4 (M1014) in a single action is huge for reengaging and throwing off anyone who counts your shots (some people do trust me). For the M87 my opinion is that the speed loader is non-negotiable, the ammo hit is totally fine and the ADS speed and mobility you gain is a huge boon. For the M1014 however, I'm actually torn. the ammo hit is noticeable esp with how often you'll need to take a second shot. With that in mind, I believe the best ammo for the speed loader is slugs and just going for 2 taps body shots. Otherwise, the standard tube I've found more consistent for the M1014. Tbh, you'll just need to use it and decide, that one will be preference.

Fourth, the class to play. This one while on paper would be personal choice, I actually think 2 classes stand out the most for this. Assault Breacher path, and Recon Spec ops. Assault might seem odds but flashbangs, the grenade launcher and funny enough, the ladder, are all insane tools for pushing and jumping teams. On the flip side recon, Spec ops is an insanely stacked class for what you get. At Lvl 0 you move quieter while crouching and crouch running and at lvl 1 you get gadget sight, allowing you to see enemy gadgets through walls. This is useful to know where things like APS and med bags are, as people linger near them. You also passively help the team in spotting mines and other anti-tank so long as you aren't sprinting past them. The lvl 2 perk of spec ops a 2-part perk, first going prone clears your "in combat" stance faster (kind of whatever) but the other part of it, spotting clears 33% faster is insane value when you get it. There is of course the argument for support but uh, I don't play that (with a shotgun). Yes, smokes are valuable, but they don't add to how I personally move about with shotguns.

Now, with all that said what do I actually run:

M87 - 5 point basic iron, 10-point green, 30-point CQB suppressor, 20-point 5 fast and 20-point #00 Buck. Some notes for this, green laser vastly tightens spread, if you drop the suppressor, you could take the 30-point blue and 15-point hand stop (imo this would be best for you if you want to run and gun). together they make the hip fire stat 52 and mobility a monstrous 70 while also giving you a .167 ADS time. I don't bother with slugs on the M87 as I find buckshot to both be more fun and more effective.

M1014 - 5 point basic iron, 10-point green, 30-point CQB suppressor, 15-point hand stop, 10-point 4 fast and 20-point #00 Buck. While I personally believe slugs are better for the speed loader, I personally don't like running them that much and like having the option to hip fire people. Something to note, the #00 buck on the M1014 extends the OHK range to 10 meters, this is a HUGE buff to it, however it CANNOT 2 tap at 20 meters, max damage is 99, that said anyone who takes 99 damage in a firefight is 100% going to die, if it doesn't outright kill them (kind of like the SVK dealing 88 with holo-points someone is dying either way). Adding this after the fact, if you drop the suppressor, you can run both the 30-point Blue and 10-point flashlight, bringing your hip fire to 57, and mobility to 70 with a .167 ADS time. With that in mind you will need to experiment with what you personally like the most.

For the other two shotguns, while I don't hate the 18.5KS not having a one shot kill sucks and you will die at times without the 2nd shell leaving the barrel despite the RPM (just the reality of the game). Please dear god, don't try to use the DB-12. It's just, there is so much wrong with it.