If looking for breeders, the best place to meet them is a cat show. It's a really great way to get to chat to people, and good breeders are happy to recommend others to you if they don't have exactly what you're looking for. You may also run into people showing cats in the alter classes who will happily recommend the breeder their cat came from (I've met up with Sonic's breeder at shows as I like to go watch even though I don't show, and on a couple of occasions I've been more than happy to recommend her in person to people at the show enquiring about her cats).
You can also contact various breed clubs who will have kitten lists and rehoming lists, they will likely know who has cats and kittens available of the breed they represent.
No matter what someones cats look like at a show though, the most important thing is temperament, a cat can be beautiful as anything but you need to be happy sharing the next 15-20 years with it! The best way to judge is to see the cats at the breeder's home/cattery and see for yourself how they interact with each other and humans, if that is at all possible. Personal recommendation is also useful but unless you already know breeders and the families their cats have been adopted by it can be a little tricky. But definitely a cat show is your best place to start asking around!
Can't help with the shelter aspect, but pick one that is clean and where the staff and volunteers can give you lots of information about the cats under their care, and will help you pick one out