for me..reputable breeder should have all these criterias :-

1. Provides a written contract of sale with a health guarantee and written instructions on feeding, training, grooming and care
2. Provides access to the mother (dam) who should be on site and exhibit a healthy, happy temperament
3. Does not sell kitten until they are at least 4 months or older
4. Shows you where the kitten are kept. This area should be very clean
5. Provides you with a record of the dates and types of vaccinations and de-worming done, feeding instructions, and a "blue slip" to apply for registration or help you in registering your cat.
6. Is able to prove he has performed pre-breeding health checks on the parents
7. Provides references of people who have purchased kittens in the past, the names of other breeders, and the veterinarian who provides care for the breeder's cats.
8. Offers a return-buy back policy and make it clear that his/her responsibility continues as long as the cat is alive. They should be available for advice whenever needed, and help you over many rough spots.
9. Is involved in some way with rescue organizations or support them
10. Abides by code of ethics, typically by belonging to a breed club or association
11. Is very knowledgeable about the breed he or she is selling
12. Requires or encourages the neutering of all pet-quality or show-quality (not for breeding)
13. Sells kittens only to approved buyers and never sells to brokers or kitten mills
14. Can discuss socialization of the kittens and can make recommendations for their continued socialization and training
15. Usually breeds no more than two breeds.