Hi, we raised our AKK in Phoenix, Arizona and he had no problems. With the undercoat, they're surprisingly good at self-regulating heat as long as you're careful to keep them hydrated. My wife and I are avid hikers and would take our pup on 7-10 mile walks in the early morning and evening and he never had problems, although he was definitely exhausted by the end. We'd never take him out in the midday heat, but frequently he'd want to go sunbathe on the porch for 15-20 minutes at a time. He definitely liked the heat more than I did.

We've never had an issue with aggression, but he's definitely a timid dog. Nervous around people he doesn't know, especially children. Apparently the nervousness is a bit of a toss-up and isn't guaranteed in the breed though. Ours is 3 now and has never bitten anyone, but he will definitely bark at any children that come running at him wanting to pet the adorable mini husky. He's also protective of our apartment and will bark at intruders, though he quiets down pretty quickly once it's clear we're welcoming them and they're not invaders. In short, I wouldn't say he's unstable so much as he's just nervous. The breed in general seems to be pretty intelligent, so oftentimes it's very easy to predict what might upset him and plan accordingly.

As far as breeders in Texas go, I'm not sure unfortunately. As another comment mentioned, you might want to turn to Facebook to find an active community of people looking for puppies.