I want something that could be used for HD
I'll offer a few thoughts. Take them for what they are worth.
The sub 2K could probably fill that role. It is very compact and handy, you could mod it for a light, and it has a good mag capacity, and in my experience is very reliable. However, there are better choices. Despite its overall build quality, it most likely would survive an actual HD encounter. Much, like with a prize fighter though, most of the real wear and tear comes in preparation and training. I'd wager the sub 2k would not fare well after very much serious training. So if the sub 2k is of questionable quality what is a better choice?
First, I would push back a bit on the idea of a pistol caliber carbine. There are a lot of discussions out there already but I'd be inclined to go with a real rifle round in a long gun. It offers notably superior terminal ballistics. It posses less over penetration risk than a 9x19 or 40 S&W JHP. A rifle round does have more expensive ammo for training. It also can have more blast and noise. Weighing it all out a real rifle round is my choice.
If I were set on a PCC, I would probably go with a
good AR, in 9x19. Having shot real MP5s a fair bit, I like that gun, but I like the AR better. Also the HK clones range from good to crap, so do your research if going that route. Most of the semi uzis I'm familiar with seem to be reliable guns, but again I'd prefer the AR. It is notably lighter and easier to add optics and a light to. I had a high point. It was ugly as sin, but reliable and more rugged than the KT. It only had reliable 10 round mags. I would never count on a pro mag. While there is a HUGE price difference, for a dedicated SD gun I would again prefer a good AR. I'd probably go with an AR, but I'm familiar and comfortable with that weapon, and it fits my preferences better than some of the others. Again, I'd much rather have it in a real rifle caliber though.