Just my opinions only, as I don't know the prospective or possibilities for the would be market. From a cattle farmers perspective, the obscure breeds would be very limited in what you could do with them outside of direct marketing some beef. There may or may not be a good demand for the breeding stock. I know from seeing them sell at the stockyards on occasion that the "mini breeds" along with Belted Galloways, Scottish Highlanders, Long Horns get docked considerably. Waygu is an interesting option as well, I don't know how well received it would or would not be, it would be docked at the stockyards like the others as well. I will say that if you have a market maybe even a local farmers market, would be a venue, that there are folks who sell beef at some of those. We sold produce at our farmers market, there were some folks there that sold beef pork, lamb, and goat. Some advertised Angus beef, and one vendor raised Bison. I have never seen the outfit, but a farm in a neighboring county raises and direct markets Texas Long Horn beef, the have some interesting information about the beef on their website.
I have a few long horn cross cows, only one with horns, had a purebred one but she got struck by lightning last summer. The horns make management a bit of a challenge so that should be a consideration if choosing them.
If we had of continued with the farmers market, I was thinking seriously of adding beef to our stand.
My plan was likely going to be Hereford beef as that is what most of our cattle are at this point, and possibly have an option of Longhorn or Longhorn x Hereford, if the demand had of been there.