This one is rated for up to 14lbs...
http://www.petcasa.com/catalog/produ...products_id=56
They also sell on eBay...
http://stores.ebay.com/USASHOP78
I haven't ordered from them. But I'm really thinking of buying one from them (I can't believe I don't even have one puppy bag yet!!!) They seem reasonably priced.