Doan's nursery in Belt line road in Irving has many cocktail fruit trees. I would suggest to check this nursery for fruit trees, flowering plants and tropical plants. Be prepared to wait to get help and also make sure that you are getting the right plants because many of the plants don't have labels/pricing. I also noticed that many fruit trees are from California growers, so not sure how they would grow in DFW. Moreover, they do not give any kind of warranty to the trees.

We feel your pain Our neighbors let a bird planted Ca Oak start, they are on the city side of the line, we are in the county. Those oaks are highly protected. It has almost all of the massive growth on our side of the fence and has destroyed an antique horse stall, favorite apricot and several other fruit trees. We could probably apply for permits to prune, pay for an arborist etc....but, because of the lack of thought in planting I am afraid of liability when the tree splits in half and takes out both of their rentals. So are not touching it. The condo association on another side did the same kind of thing, planted giant fir trees to block the view of our old house. Granted at the time my dad and the developer where having issues and my dad was not in to maintenance... But we now have a long section of the lot that is in heavy shade. They also over water their lawn massively, they have their own well, so our plum seem to rot before they ripen-they are close to the property line. On the plus side, our blueberries like the fir needles and extra water. And where they skipped the firs, we put in a citrus grove that can enjoy some free lawn water once they get bigger. Our Veggie garden is right in the middle of our lower yard and new fruit trees are being put in where we control the water and the sunlight (well other than the new citrus grove)

I live in Rio Rancho, so I understand the fears! Someone I respect uses the really big Xmas lights, the old-fashion ones, strung through the trees after Xmas. If they bud out and a freeze is anticipated, she just plugs them in...they put out a huge amount of heat, just enough to keep the buds from freezing.

In zone 7B, it is unlikely that a generously sized container - like one suited to growing a dwarf fruit tree - would freeze in winter. And if you use a high quality potting soil, drainage shouldn't be an issue so they should be able to remain outdoors, exposed to the elements, without worry. I grow a lot of trees in containers, some much more sensitive to cold temps than most fruits, without worry. The only ones I've lost (and it hasn't been many) have been through my own negligence/lack of care, not winter issues. There are concerns with growing trees in containers but that is more to do with the correct type of potting medium, fertilizing and repotting/root pruning than cold issues with such a mild zone. The Container Gardening forum has a great thread on growing trees in containers - you might want to seek that out for additional info.