Great advice from Julz and jwash and everyone!
My "dream puppy" and what I told the breeders I talked to when I was looking for Baby Ava was
a healthy, small girl (under 5 lbs as an adult) with big eyes, small, well set ears, short legs, as long as she is high, cobby body, silky, thick coat, short snout and a spunky temperament.
It took me six months but I found her in Ava and then some!! I really got lucky in a sense but you really have to stick to your guns and not go on impulse when you see the first cute puppy because they are all cute. The size was not as important to me as the baby doll face which is a really short muzzle without being too short as to affect her health, big eyes and lots of thick hair on the face. I think Teddy bear is more of a wide face and "pixie" is really small features like you find on an "extreme tiny" (under 3 lbs as an adult)
I started a thread a while ago that you may want to read about How to: Have the Best Chance of getting a small puppy who will be a Small Adult
http://www.yorkietalk.com/forums/showthread.php?t=9159
Here is a pciture of Ava at 6 weeks and another at 11 weeks so you can see how she has evolved. Good luck and PM me if you want some breeder references for this particular look.