Talk to your
Tractor Supply to see which hatchery they get their chicks from and what your options are. Different Tractor Supplies get their chicks from different hatcheries. I can tell you where mine gets them, but I have no idea where your's gets them. Some
Tractor Supply's will order specific chicks for you and some will not. If I order through mine, I have to order a minimum of 25 and they are delivered by mail to my address. Not much help.
What options you have to get chicks will be different at your
Tractor Supply. Mine puts all red chicks in one tub (not just sex links, all red chicks), bantam in another, and all others in a third. Makes absolutely no sense to me, but that is the way they do it. What I am getting at is that each
Tractor Supply does it differently. If you talk to them, you can find out what your options are. And you may need to search around for someone that actually knows what they are talking about. Some employees do, but some don't.
Hatcheries do select their breeders to the Standard of Perfection. But instead of keeping one specific rooster with one or two specific hens, they keep several roosters with a lot of hens so the controls are not as tight as with some breeders. Your chicks are not as likely to be show quality. Also, even the best breeders hatch out a lot of chicks and reject most as far as showing them or breeding them. You don't always get grand champion, perfect Standard of Perfection chickens from even the good breeders.
Not all breeders have the same expertise or goals. For example, some breed Welsummers to win grand championships at shows. Some breed them to win grand championships and lay dark eggs. Some breed them to lay dark eggs, not win championships. Some people order hatchery chicks, breed them without a copy of the SOP around, and sell those as Welsummers.
If you can find a breeder that knows what they are doing and is breeding toward the goals you want, you can get great chicks. Their worst culls are almost certainly going to be better than almost all hatchery chicks.
I don't know what the categories are in the shows you are talking about. Many county fairs have categories for 4-Her's to show about any chicken, even a sex link. But some shows are very strick about which birds can be shown. For any of them, check ahead of time the medical requirements. Most require certain testing.
Not fully understandng your goals and plans, I would suggest trying to fine a breeder in your area that produces show-quality BR and get a few from them to show. You can get the rest from
Tractor Supply.
Good luck!