For the refractory casting, local pottery supply
shops, check yellow pages.

I'm sort of following the Gingery route, but
chose a discarded water heating tank for the
container. Search the yellow pages for repair
shops for water heating tanks, they usually
have old ones laying around the back of the
shop for recycling.

If possible, get an electric heater, the
gas ones have a metal tube in the middle of
them that are a PITA to deal with. I used
a hacksaw to cut it, and welded the bottom
shut afterwards.

Tom. (Boston)