At 30 yds, I would say that just about any of the current crop of LED drop-ins will do. Just have to get one that works in weaponlights. Many of the P60 drop-ins have continuity problems with the weaponlights, but work fine in standard handhelds like the 6P.
The issue isn't the lethality of the pellets at 30 yds.
The deal with a 30 yard shot is that your pellet spread is potentially larger than your target, which may present a downrange risk.
Not sure what you mean that your shotgun doesn't have to be "dialed in at 30 yds". If you mean that you don't have to aim, I disagree. This isn't trap shooting, where you need only to have one pellet barely clip the clay bird. For effective self-defense, you need to have the pellets hit the key structures that produce rapid incapacitation. That requires both accuracy and projectile penetration.
For 00 buck, you have 8 or 9 .22 caliber balls. With substantial pellet spread, you also lose the synergistic effect of the multiple pellets striking the target and move toward separate .22 caliber hits. I suppose a Vang Comp'ed gun can put all of the pellets on the target, even at 30 yds. But now you really can't rely on pellet spread to get a centered hit.
My personal preference is to use a shotgun like a rifle and use slugs.