How committed are you to the breed? If you intend to keep them in the future then selecting for easy lambing, good mothering, prolificacy and longevity in the females would be advisable and buying or hiring a ram from an established and highly regarded breeder would be of benefit to the flock in the long term, as you'll find the flock improves with each successive generation. Ryelands are a Down sheep, therefore a terminal sire breed, which bring good conformation and hybrid vigour to the lambs when a ram is put to a Mule, hill or mountain breed. The Southdown, Hampshire Down, Dorset Down and Suffolk are all used this way but there's no reason why a Ryeland shouldn't be as well.