Discus fish have a reputation for being difficult fish to keep, but most discus available today do not deserve that reputation. Even though there are sometimes wild discus fish offered for sale to stores by aquarium fish wholesalers, the vast majority of the discus for sale in the aquarium hobby/industry are commercially raised. The only requirements they have is that the discus fish like the water temperature to be in the low 80s, and they really should have their own display aquarium, so they do not have to compete with other fishes for food. Discus need to be fed often and well, but all of the discus I have kept took frozen and dry foods.
As with other fishes, such as angelfish, guppies or cory cats, the best source you could find for supplying discus is a local fish breeder. There are also a number of fish breeders who advertise in the fish hobby magazines and on the Internet. The problem with going to fish breeders beyond your locale is that you may not be able to buy fish from them at much less than what they sell for to the general public. Therefore, most fish stores will end up buying their discus from their regular fish wholesaler.
Most fish wholesalers carry discus fish bred in the Far East – Thailand, Singapore, China, Malaysia and Indonesia. The problem here is that many of these discus have been raised at very high temperatures with massive feedings and massive water changes. In addition, the Far East discus fish breeders are generally known for frequently using hormones to improve the color of their aquarium fish. The trade-off is that Far East discus will be half the cost of locally bred fish or fish that are imported from Europe. My advice is to bite the bullet and pay more for discus fish from Europe or from a local breeder.