I am using the slo-set from artmolds, is there anything better out there that would allow me to do multiple castings? It seems to get expensive and time consuming to do a separate negative for every casting.

You can use a product called Body Double, its' a skin silicone rubber that can be used for making lasting molds of the face, hands and other body parts. Copies perfect detail from any original. You can cast anything into a Body Double mold and make many castings from a single mold - not just one. Finished molds last a long time.