Breeder part really depends on what's your goal for the fish.
Are you looking for good quality fish for breeding or one you like for a pet?
The quality of the fish is something you really need to look for by studying the pictures. Look at the form anf finnage of the fish and decide which best suits your breeding goals.
If you're looking for a pet... it doesnt matter! Just pick the one you like best!
If you look at the sellers feedback you will notice that most breeders are very responsible about their fish and that most people have smooth transactions.
If buying from the US, Martinsmommy is an awesome breeder with many winners under her belt.
If you're buying from outside the US, make sure you're aware of all the extra expense involved in importing a fish.
Not only will you be paying for shipping to you but you have to pay usually $5 per fish to the seller and then pay the transhipper for mailing the fish to you.
This is a link to transhipping info, it will give you and idea: http://bellsouthpwp.net/J/e/JennViv/...taTranship.htm