Some good places mentioned in previous post as far as locations in buying the molds.
Determine what weight sinker you usually use (and Lose)then buy that mold first. Many molds come with two or three diferent size sinkers in the same mold.Some production molds just have one size for example all 6oz, or 8 oz. Some all pyramid some all bank.Pour the sinkers OUTDOORS only. Cool weather a few cold beers and bucket full of lead should do the trick on a Saturday morning.Good Luck and Enjoy.