Theyre not very common in fish shops. I ended up getting all of mine via Aquabid. Most are best kept in a species only tank. Some can be fairly territorial for little guys. They are usually sold in pairs. Keep in mind, with some species, you most likely would not be able to keep more than a pair or a male and a few females. (I learned this the hard way). Go and visit the American Killifish Associations Website. They have great beginners articles. They will help you decide what you like and can keep. Then you can begin your search for breeders. The site will also lead you to some breeders.