Petrageous.com - Functional, whimsical and outrageous pet products.
those are the cheapest, dont know if you like them or not, my favorite is
Dog Pajamas - Tinkerbells Closet Dog Boutique Custom Clothing and she sews everything herself so she can make them whatever size you need. also
PoochOutfitters.com is good. sometimes on etsy you can find great deals. i dont mind helping you out as a seller but the 2 i can get wholesale on have min order amounts of $100 or more.