One more thing for OP... Be sure you are selling what you say you are selling. (Not that you'd do this, I just need to rant a minute here.)
The birds I got from the breeder aren't what she said they are. The bottoms of the feet of Australorps should be pinkish white. Not yellow. So I don't have...
Maybe they had friendly, gentle ones, but I have a roo who is... tolerable. And he is the nicest of the 3 BOs I got. The other 2 are buried in my garden.
Here are my thoughts, FWIW. I know little about breeding, genetics, or the business end of things.
If you want to really make a business of it, you have to get all the certifications/licenses taken care of. What are they? I have no idea. But you don't want to go to all the work and expense...