We use a couple of different vendors & recommend these ones highly:
Dog Bows|Yorkie|Dog Hair Bows|Shih-tzu|Topknots|Maltese Pairs AngelzBowz | Beautifully Handmade Dog Bows
on Etsy: BlueMonsterBows06 (small infant size snap clip bows)
on FB: Preciuosly Adorned Designs by Patricia Burgess Reinhold
We also use BowBiz too!