In 1973 the Rare Breeds Survival Trust identified Hebridean sheep as a breed in danger of extinction.
Only a few flocks remained in West Scotland.
Fortunately, these flocks had been virtually wild, with little if any management, and so the characteristics of the sheep had probably changed very little since their arrival.
Since then the Hebridean Black Sheep Breed has been revived, and it is no longer regarded as rare; it is kept in many parts of the world, now including its
native Hebrides.
That might be a bang up choice for your purposes. They are very hardy.
Redhawk