Personally I've never seen a shihtzu with long hair, the reason I say them is because they are really cute and I always see men around here walking them. They shave their bodies and have a bit longer on the head and tail
I just thought I'd suggest one because they too stay small and don't shed.
You want to know more about a yorkie? Well, once you get one, you will be addicted!! You will want another one, you won't want to put your baby down or leave it at home. You'll rush home after school or any other outing just to check on your baby. You will get TONS of loving from your new baby as well. Mine will sit and lick my face for hours if I let her, she is the most loving creature I have ever seen. She is a little shadow, following me from room to room. She can be super Stubborn but like I had mention mine came from a very bad situation and well she is just alot more calmer and "aware" of her surroundings. I don't know if you've thought about a rescue? I feel those ones, are very grateful for a loving home and will love you unconditionally in return.
I'd also suggest if your going to geto ne, don't fall for false advertisting of "teacups" theres no such thing and it's alot easier to care for one who is on the higher end of the standard. I think 5 lbs is perfect. Mine is about 4.8-5lbs. She is still very small but it's so much easier and less worrying about her hurting herself. These aren't dogs that should be jumping off a couch or bed, they can hurt themselves very easily, they think they are a big dog in a little body!