I get my sweaters from SpoiledYorkies.com they have some really nice warm sweaters with leash hooks. We also have members on here who make very nice doggy clothing. I have ordered from Joy, she does really really good work. ummmm we have Shanatink who has beautiful clothing @
http://www.tinkerbellscloset.com/ I know there are some others that I just can't think of at the moment. But It's a start,,, If you go to search and look for clothing sites there are many different sites there. I'm sure you will find something there.
http://barkindogclothes.com/ has some really cute sweaters. Good luck with your search.