for home defense, the Hi-Point, if you load it with CorBon 100 gr jhp's (1650 fps from a carbine barrel). The 9mm carbine has considerably less blast and flash. A lot of the 30 carbine softpoint ammo is wussified down to 1700 fps or so, I have heard. BAll ammo in the 30C aint much. If you use the softpoints, the velocity is down below reliable expansion speed (1800 fps) at pretty close range, like 50 yds.
Cast bullets are much easier to make work in the 9mm, and jacketed carbine ammo aint welcome at a lot of indoor ranges. You can find used, good condition High Point carbines for $200, with the laser sight thrown in, sometimes.
Take a look at the ballistics charts sometime. the 30c falls off like a stone at 150 yds. It drifts badly in the wind, too. I can see it failing to penetrate heavily quilted winter wear, at 300 yds or so. If you don't flip of the "long range" wing of the peep sight, 200 yds is a long, long shot for the 30c. The 223 outranges it by a wide margin. I'd say to get an AR, actually. If you suppress it,. the HP is going to work better with subsonic loads, and the laser sight might (don't know) help "clear" the silencer. I know that if you put a suppressor on the 30c, it's still going to have sonic crack with factory ammo, and when you look thru the sights of the 30C "wearing" one, you'll be looking at the back of the suppressor.