Well, our views can definitely change. Yes, you should have put reputable breeder...even if you wouldn't consider them reputable now.
To clarify; By "reputable" breeder, let's say we mean "has a reputation" of showing dogs, breeding for breed standard, and does some health testing. These are breeders that are involved in their local breed clubs and are very intertwined in Cavalier happenings.
BYB would be someone who breeds dogs at their home, maybe a couple litters a year at most, does no (or little) health testing, is not involved in the show ring, and usually says something like "I just love Cavaliers so much I wanted to breed my dog so my friends and family could have one...". Some come with pedigree and/ or registration papers, some not.
Pet stores and brokers would be if you bought from a pet store OR on the internet from someone you never met, OR if you met someone in a parking lot or the airport or something and they had several Cavalier pups- this is most likely a broker. A broker can also be someone who has many different breeds of puppies in one location, whether at their home or listed on an internet site. This also applies to any dog you KNOW came from a puppy mill.
Rescue- this can be a challenge. Only put rescue if you DO NOT KNOW the background of the dog. For example, my Winston is a rescue. However I know he is from a BYB. So, I would put BYB. The foster dog I have now is from Petland, so I would put petstore/ broker. Does that make sense?