I would definitely go to the bird show. While you may not find a youngster to take home with you that day, I'm sure you will be able to make contacts with some breeders that are 'relatively' near you who either have babies at home or have clutches planned for the year.
While there may be chances of exposure to illness or whatever, I doubt its all that different from a dog show. Most respectable breeders that are there to win will not be taking their sick birds or otherwise unhealthy birds to the show. I'm sure they have both their bird's best interests as well as competitiors interests at heart.
Be sure to talk with the breeders whose birds look the best and biggest and who are winning the classes. Chances are they are more knowledgeable and have birds with good pedigrees. I don't know where you located, but birds with Feret, Short, Maple, and Greeson are some breeders to look out for in cockatiel pedigrees.











