As far as powder is concerned, in the States, Graf or Graff's will ship it to your door.
Checking your State's laws, though might be a good idea if you get together with a bunch of guys to buy, say 25 pounds. Purchasing larger quantities is a way of reducing price per pound due to the Haz-Mat fees. Since the order will be in one person's name, some States have laws against that person selling to others.
BTW - welcome to the forum.