That's good to hear but being such a new member, we have no idea of your level of experience. I was guessing that because you are asking about black & tan dogs & appeared to be confining your search to Devon that perhaps you were new to breeding, hence my reply to you
If your bitch's brother is competing at Crufts, can the breeder not help in your quest or did you breed him yourself? As this is a minority colour, you will find there are not huge numbers of dogs to choose from and of course there are other factors to consider besides colour - it would be a bad idea to select a dog for colour if he didn't complement your bitch in other ways (pedigree, health results, not having the same faults as your bitch etc)