greyfieds is right, that a really excellent Barred Rock is hard to find. Mine are utility, egglaying Barred Rocks, although a couple of my girls have better barring than most hatchery birds. My main point was that you should find what you love and breed that. I happen to love Barred Rocks. There are breeders that have eggs/birds in the Barred Rock category like Dick Horstmann and if you wanted to breed BRs, I'd start with great stock, never hatchery stock. If you don't like black, white or buff, then it doesn't help to breed those. I personally would do what I liked most, even if it was difficult.
You can also breed for egglaying capability, not just for perfection in conformation. It's hard to have both. I don't want to show nor do I breed for show with my Barred Rocks. I breed for body type (stocky, not lanky like some), temperament and egglaying. That is just as legit as breeding for perfect barring; still, I would love to see better barring in these hatchery birds!