This checklist can also be used for other breeds with some adaptation as, for example, not all breeds test for HD.

There will be a majority who wonder, why on earth should I have a checklist, I will only buy a companion cat that will be our new family member, not an kitten for exhibition or to breed, why is it so important to check all those things?

Buying a purebred costs money, a lot of money, how many of you would go out and buy a car without seeing inspection paper or number of miles driven?
Even if you are only going to have the car to go shopping and drive around in for work, you will probably check both reliability and number of miles, if it got any dots on the inspection, how well serviced it is, or ???
Why in the world would you NOT do the same thing to a living being, a family member?

 Do not agree to pay for a place in a queue for a kitten, this is something that is a lot more common outside Scandinavia and northern Europe, there are many breeders who do not charge for you to stand in line with them, contact one of these instead.

Do not agree to pay anything before the kitten is born! This does not occur in principle in Scandinavia but seems to be more common on other continents, preferably you pay deposit after visiting when the kitten are at least 4 weeks old.

Check out the pedigree of both parents and the offspring, of course the cat you buy must be registered in an association or Indenpendent club.

Require to see that HD test has been done on the parents within PawPeds, this can be seen online, via OFA the breeder has a paper that you can see.

Require to see that HCM is done on the parents, these are done before the first mating, then approximately annually up to 3 years and then once at 5 years of age.
Approximately this is done at 1, 2, 3 and 5 years of age. Sometimes it might be a gap, but the parents should not be 5 years old, and tested at 1 year of age and nothing after that.

DO NOT pay an overprice for a color, no color is unusual enough to justify an overprice even if some breeders want you to believe this. Feel free to check what the price for  a company kitten,  is in your particular country, it might vary a bit of course but not to the extreme. 

There are lots of good breeders in your own country, DO NOT start by Importing, this is for breeders with experience and knowledge!
Seemingly lower prices might attract but in the end it often becomes an expensive lesson learned.

Buy a kitten close enough to be able to visit and meet the breeder and your future new family member, if a meeting is absolutely not possible due to distance or otherwise, a video chat with the breeder can be made, where you can see the kitten live and get to know the breeder. If you can not visit, make sure you go to the breeder's house to pick up your new family member.
The kittens should be clean and nice, clear eyes, clean ears, no signs of diarrhea or the like. Ask to see the mother, preferably the father if possible, to see what they look like and how they seem to be in the temperament.

No kitten may be delivered before 12 weeks of age, according to the Animal Welfare laws here!
If they are 13-16 weeks, it is only an advantage.
Not all countries have an animal welfare law that says 12 weeks, this does not mean that you as the buyer must agree that the kitten is delivered before 12 weeks, they need to be with their mother for at least 12 weeks.