I would call your local speed shops. Try
http://goodies-speedshop.com/ They seem to be closer to you. If they dont carry it I imagine they know the local guys that do since they deal with race cars. Or if you want I could pick you up a drum when im in there on Friday. Not sure if that saves you much traveling, I live in Half Moon Bay and work in Foster City. You wont go through it quick though, All you gotta do is pick up a couple of drums once a year.