
If you want one from a breeder then you're going to have to be very choosy, so many are being bred by breeders that just want the money and don't care about health testing, temperament and construction, but then they aren't the ones paying the vets bills if the pups get sick or need surgery

A good way to find a good breeder is to contact the breed clubs, you will also be able to ask or read on their websites about health testing that the parents should have certificates for. Be patient and be prepared to wait for a well bred pup, it'll be worth it in the end
http://www.the-kennel-club.org.uk/services/public/findaclub/breed/list.aspx?id=3080