They are easy to breed if you maintain them well they will d the rest. Keep your water chemistry stable, use gravel or sand-it is a must-, have plenty of plants real or plastic and objects for them to feed off of. They will eat veggies, crushed snails, flake food, shrimp pellets and the like. Don't over feed, I feed mine enough for 4 guppys 2 x weekly. I have about 70 breeders. Use a sponge filter or two, I use the sponges rated at 80gal x 2 in a 20L. Use floating plants or devices, they like to surface skim. I use duck week and a plastic coffee can lid cut into micro lilly pads.
If you plan to sell them I would take a dual approach. Use two tanks and once a month grade out the most colorful and put the culls in the other tank to sell for feeders or just as micro shrimp. If you don't ruthlessly remove the low grade animals you will lose the color fast. Keep in mind these guys get to a point and breed like crazy.