You can go to this site and put in your area information to find a store near you that sells California Ntural, made by Natura:
http://www.naturapet.com/display.php?d=stores-tab
Shampoo is another common "itch maker" -- what are you using to wash your baby and are you rinsing twice as much as you think necessary to make sure to get all of it out?
Another cause of itching is dry skin. If you think this is the cause, the addition of some essential fatty acids will probably help. Ask your vet what he would recommend, some use professionally developed capsules, others use Vit E, fish oil, flaxseed oil, olive oil, even vegetable oils, but I would want to get your vet's take on it. For my own dry skin I like the Black Currant Seed oils.