This is my favorite place for sweaters:
HAPPY DOGGIE BOUTIQUE - UNIQUE HAND KNIT DOG SWEATERS - CUSTOMIZED
They are hand knitted hoodies and I think that the price is pretty good too considering that she makes them herself. Here's a pic of my Lily in one. Lily is just under 2lbs and wears the XXS so they should fit your little one.
Great post! I'm always looking for recommendations on places to get winter clothing for the furbutts!