You'll find hass seedlings here and there throughout south florida. Lots of folks buy the hass at the supermarket and plant them out in their backyard.
I'm personally very attached to the FL hass though. It's very productive, it's dwarfish, it bears over the late fall months, and it's incredibly delicious. Being that it's slow growing, it does require some patience. But the long term benefits of not having to deal with a gigantic avocado tree far outweigh the upfront investment of patience.