I am building an AR style carbine for home defense. Wil be using a collapsable stock, 8" barrel with suppressor. I have hundreds of hours of tactical carbine shooting, and maybe a dozen hours with a handgun. And I know under combat conditions I will be far far more accurate with a carbine. I will be going either 6.8 or 7.62
Beretta XC4 45 ACP with light and foregrip. Only 8 rounds in a mag but it should be enough. It's a great gun, very reliable and easy to shoot and packs a punch. Also have a XD9 as back up.