As a generalization, hatchery birds are going to be pet quality and I suspect that many are not purebred. Since they tend to be both much smaller and heavy egg layers, I am suspicious that leghorn has been bred in to increase egg production.
Fire tigeris has had bad luck. My exhibition birds have no health issues and temperaments are lovely. Every show breeder I know (and I know many) will cull for health issues and laying problems. With one exception, every show breeder I know will cull for bad temperament, and that exception catches a lot of flack from the rest of us.
Not every "breeder" will produce good birds. There are those who buy from hatcheries, breed those birds and call themselves breeders. All they are producing is more hatchery quality birds. Breeders must be interviewed before you buy.
If you want to buy mail order chicks, the only place I know that raises and sells show chickens mail order is Urch/ Turnland. Other than that, you'll want to look for a serious show breeder in order to buy quality birds.