Thanks for the imput BH . . . sorry the link didn't work, I keep forgetting to check them after I post to make sure they do.
Part of the problem is the size of a conventional oven, which has too much air to heat. So one solution is to reduce the interior size of the oven. As I said, I finally invested in a pizza oven, a Bakers Pride countertop, where the space inside it is only about 6 inches vertically so it can run on 120v (they have a 220v option).
Anyway, the administrator at pizzamaking.com is pretty scientific about figuring stuff out, and managed to get great results with quarry tiles. Here's the link that explains how he did it:
I've been investigating soapstone, which apparently is just about the best material there is at absorbing heat quickly and radiating out slowly (here's a site that gives a great explanation of why: http://www.woodstove.com/soapstone_f.html
.) One place I found using Google, sells tiles of it for countertops, so I am going to suggest in the above thread that he consider using soapstone. I use it now to serve pizza on . . . it is awesome for keeping it hot while serving.