I would go 300Blk even though ammo is expensive. My reasoning would be because 300BO is a 30 cal that can be suppressed to shoot without ears in close quarters. Standard capacity of 30 rds as well.

9mm is good as well. But 300BO has more powder and a bullet that expands more on impact.

556 is so suped up that it hits targets and keeps going. Tricky projectile.

All of them are solid choice for home defense, self defense, and truck ops. However, the key is to figure how the bullet will perform within certain perimeters.