If you want to buy chickens at Ohio you can take a chance that something you want will be there or search for breeders to talk with before the show so they can bring birds.
There are many ways to find good stock. Breeders can be found online, through breed clubs and area clubs, magazines and in the poultry press. But the best way by far to get birds is to enter chickens in the show, get a show catalog, be nice/talk to people and pour over the show catalog (which can be yours for the price of entering chickens at the show). The catalog has names and addresses of everyone who is showing. Just connect the bird you like to the exhibitor's number and bingo instant contact info. However it is so much better to talk to people and network! Besides it is fun.