Try Safeguard Goat Wormer. Liquid and easy to give. Know a guy who has 100 puppies right now and he says he has had good luck using it 3 days in a row.
Probably at most any feed store. Im not real sure but don't think you can overdo it unless you get carried away. I'd say 1-2 ccs per pup depending on size. I'm not real sure exact amounts.