Hi, there are a number of litters listed here. You will also find a comprehensive list of breeders here. I would also suggest you get in touch with one of the breed clubs listed here. Bare in mind though that you may well have to be prepared to wait for the right pup for you!
Hi try contacting the Weimaraner Club of Great Britain and/or the Weimaraner Association the two national breed clubs who will put you in touch with members who breed. Members will abide by the codes of ethics/conduct by ensuring they do not mate bitches prior to 2, after 7 or have more than 3 litters in their lifetime. They are encouraged to have their breeding stock health checked (breed average 13) and to breed only from animals that fit the breed standard.
Reputable breeders will not breed until and unless they have sufficient enquiries to warrant a litter and waiting lists may be long.