I have a pistol grip w/ stock, I wondered about a laser for aiming from the hip?
I know that people don't recommend Slugs because of over-penetration, but what about sabot bullets?
Why in the world would you want to shoot from the hip, instead of properly shouldering your shotgun so you can properly aim it, have better control over it, and can cycle the action faster for more rapid follow up shots?
Take all the money you want to spend on the laser, buy some ammo for practice and find where you can take a shotgun class and learn how to effectively employ your weapon.
As for what to use--those low recoil 00's are a good choice. If you live in tight quarters, #4 buck can work, but would not be my first choice. #1 buck is usually considered the best load out there, though...
Just avoid birdshot, period. It's good for anything with feathers and mammals under 10 pounds; for mammals over that weight...go for the buckshot.
Slugs--well, they do have a place in home defense--and that's called turning cover into concealment tout suite. I really hesitate to recommend them, though, unless you live in a very rural area, as I do (and I don't choose them for HD, m'self...). And as pointed out above--sabots require a rifled barrel to be effective, they'll go through many walls just like a Foster slug, and are expensive as heck, to boot. Not needed for HD.