I don't breed chickens, but have bred horses and dogs for years, and I can address your concern about buying exhibition-quality stock even though you have "next to no interest" in showing. That's a COMMON thing I hear from people buying a purebred pet puppy, particularly. Please bear with me for an over-simplified take on this:
Generally speaking (please keep that word "generally" in mind--there are always exceptions), those breeders who are actively out showing their animals are truly interested in consistently pushing the quality of their own stock, and improving, improving, improving. They understand the importance of getting out there and comparing their animals with others, to prevent "barn-blindness," and to get a (hopefully) objective outside opinion on how their stock stacks up to the standard; the ideal.
The exhibition breeders should be the ones with the most at stake in preserving their given breed(s)--they will have the good of the breed at heart. And I'd wager a guess that they're not making anywhere near as much money from selling their stock as are the people who stay home cranking out babies without thought for much besides profit-margin. (And before anyone gets offended, I am NOT saying that if you don't show, you're just in chickens for the money! I've seen MANY examples of breeders here who, while they don't show themselves, they get their stock from breeders who do, and they really stay on top of what's going on in their breed.)
Exhibition breeders don't just say, "My birds are the best," they can say, "The following judges found my birds to be the best." These are also the people to be most likely to be on the cutting edge of innovations in research and health and genetic issues that affect their breed(s).
And in breeding any animal, every single one is not going to be Best In Show quality, champion-quality, or even show-quality, period. You can probably get some super-nice birds that are actually culls from someone's breeding program, simply because they're choosing only the absolute best of the best of the best to continue on with their breeding program...there should be plenty of high-quality animals left to choose from. Even more, if you don't mind disqualifying faults.
Someone correct me if I'm wrong on any of this--I'm just taking my experience in showing/breeding other animals and extrapolating it to poultry. I haven't yet decided if I'll really show poultry someday, but it's always in the back of my mind.