Hi and welcome to YT!
You will find lots of great information here. The first place i'd go when looking to purchase a yorkie is the yorkie club site.
Yorkshire Terrier Club of America there is a lot of information there about the breed. they also have breeder club members listed who abide by the standard.
Yorkshire Terrier Club of America About The Club these are the first breeders i would personally check with.
you mentioned you found a breeder that has CKC registered puppies. i wouldn't purchase a pupped that was registered ckc for reasons already mentioned. I'd look for an AKC registered puppy. Look around here on YT for more information on the breed and where to purchase from.