if there's a rabbit show in your area, that might connect you to some breeders. There's also transport folks and you can fly them on planes, too, if you an get the breeder to drop them off at the airlines. I've heard possibly can be shipped via greyhound bus as well? Not sure about their cargo area, though.
6 weeks is way too young to buy a bunny. Run away - quickly - from anyone who will sell a 6 week old rabbit. Minimum 8 weeks. Trying to get a really young one doesn't really do much good since you can't really determine the quality of their final adult coat at much less than 16 weeks or older.