Logic dictates that once you have two Golden Chocobos of differing sexes you can breed them together to make further Chocobos. Granted these Chocobo due to cross-inheritance would most likely have three wings, no feet and go "WERK!" instead of "WARK!". However I've never had more than one myself. If you still have the two parent Chocobo and a free stable, then just keep at breeding them. I don't believe there's a limit to the number of little blighters darling birds you can have.