Just in case it's hard to find, here is that thread on a good breeder. It's geared for someone who wants to breed their cat... but all the points are absolutely spot on for finding a good breeder.
For me, I wouldn't buy a cat, dog, horse, or anything unless it was within a distance for me to visit. I want to SEE where the cats live and how they are treated. I want to SEE how the breeder interacts with the animals and how they are treated. All that is going to shape their temperaments and personalities.
I would make sure to research the breed and know what defects come with them. Then I'd wait for the breeder to bring it up. If they don't bring them up without me prompting them and show me proof that their cats are tested before breeding, I'd walk away. They are dishonest.
I'd want to SEE the sire and the queen. Not pictures, the actual cats.
I'd ask if their cats are shown. WHY are they breeding. If they aren't showing their cats and breeding to improve the quality of the breed, they aren't a good breeder.
I would expect to hear there is a return policy. If the cat has something wrong with it the contract should state clearly what happens. Usually that means returning the cat for another or your $$ back.
Are they going to be there to help you after adoption. Do you have their home number and their cell number so if there are any issues or questions you can contact them at any time.