Hi
It is impossible for anyone to recommend a good stud dog without seeing your female.
The best Saint may not suit your female or their hip/elbow or heart tests don't match.
The best thing for you to do is , go to some dog shows and mark up on your cataloge a dog that catches your eye. If possible Check up on the pups that he produces, Have a good chat in person with some people at the shows that have some dogs that are going to public stud. Bring a copy of her pedigree with you along with a copy of her hip/elbow and heart test. A stud dog owner will want to see this. You can then arrange for the stud dog owner to see your female. I do not know what the rules are in England but here in Ireland we are not allowed to bring a dog that is not entered for competition.
Best of Luck