any of them are fine. Low recoil buck shot is 8 pellet instead of 9. #4 buck shot is acceptable but not #4 bird shot there is a huge difference.
Slugs you can try both and see which you like better. Personal preference is really what its all about.
The military buckshot is just 9 pellet 00buck.
I use 9 pellet 00 Buck in my HD shotgun. My go to home defense gun is a 45acp carbine with 30round mags though. 30 min slugs > 8 big ones imho.