A lot would depend (hopefully) on how the cats themselves handle being transported and exposed to show conditions. Starting them as kittens is a good way to go about it I would think, but even some kittens will not tolerate carriers and hullabaloo.

I don't believe in showing, but if I did, my cats would be horrifed and very stressed to be put through such trauma.

While you're doing your research, be sure to start accustoming your kittens to carriers, traveling and being stared at by strangers in loud noisy places.