I came across some sources which I had not seen mentioned before , which I am
passing on. I have not tried them myself.
Sassafras Enterprises (800) 537-4941. "Baking products manufactured from
Superstone, a natural ovenproof stoneware that when used in an ordinary
oven, can duplicate many of the effects of a wood-fired bread oven."
Oven Crafters. (415) 663-9010. To build a wood fired bread oven.
Sourdoughs International (800) 888-9567. "A former pathologist has traveled
around the world collecting different sourdough cultures. $10.50 each. A
descriptive brochure available."