Heavier Hollow points are the way to go.
That being said, I think a .223/5.56 pistol while having some advantages, has quite a few against it ranging from overall effectiveness to defense in a courtroom.
If you are stuck on .223 only I would personally think you would be better suited with a lighter carbine with an 11.5-14.5 welded flash hider/brake to make it over 16 inches. I think a good short barreled AR varriant in that caliber with good hollows is a great self defense weapon with the ability for multiple adversaries, limited penetration in walls, and excellent handling double duty for the spouse... Just keep a courtroom approved 20 rounder in it with top shelf ammo and save the C-mores & banana clips as backup.
Also, FWIW, dropping the bolt on an AR has great pucker factor, second only to the racking of a 12 gauge pump...