A Pistol carbine in either 9mm or 45 ACP, this will give you the ability to use the same ammo in two different platforms. Tons of folks make them from Colt, S&W in the high priced range to mid range Just Right Carbines, Thureon defense, to the low priced ones Hi-Point, Kel-tech.
To cover yourself just in case of an extended stay (say things get bad for months at a time), I'd Bump up your 9mm & 45 ACP levels to 1,000 rounds each.
I have a Bersa Thunder 380, that and the G26, these will be great for up close defense. Mag changes will be important, don't run out of ammo because of reloading just one or two mag... get 4 min.
You sound like you are in good position to keep your family safe for some time.
"A man can never have too much red wine, too many books, or too much ammunition"