You could just say you're looking for a standard size yorkie in the 4-7 pound range which should be fine for your little guy. My two are Bandit who is around 4.5 pounds and Nala who is around 6 pounds and they play great together.
You've gotten great advice so far
Keep looking for breeders who stay away from the 'teacup' term and are more interested in health and wellbeing of the puppy than size. I'm from Westchester and for our second puppy we went to a breeder ouside Albany and the pup was very reasonably priced and extremely healthy and right in the weight range.