Welcome to YT
Good for you for doing your research before you buy! I know of one YT member that breeds & lives in Portland - feminvstr is her user name, Kimberly is her real name -- I'm sure you could send her a PM. She has beautiful yorkies - this is her website
Yorkie breeders site: AKC Yorkshire Terrier breeder exhibitor of yorkie puppies - Yorkiepassion
If she doesn't have puppies available, maybe she can put you in touch with another breeder