I recommend guns with calibers that are easy to find ammo for. 357, 9mm, 45 are good choices.
If you get wildcat rounds you better learn to reload.
We have 2 Redhawks. 44 mag and 3, 12 ga. Tons of ammo for all. Wife and kids know how to use them. That pile of dog sh!t won’t get them without a fight. I might die, but 6 or more of them WILL go with us. That will do their kids a BIG favor.
For me its 38 special, 9mm, 45 acp, 44 mag, 30-30 and 5.56 in self defense gun calibers