For the wall -: I suggest using 5/8 fire guarde sheet rock then put a sheet of thin metal spaced out from the wall about an 1" or 2". The spacers could be ceramic knobs. This sheet should be open top, bottom, & both sides. As the sheet metal warms up, it creates a convection current up from the bottom which provides cooling to both the wall and the sheet metal. More heat creates more draft, faster cooling. I used to have a barrel design woodburner in a mobile home set up this way. The clearances were way too close per the specifications, but the wall stayed suprisingly cool.
For the kiln, I would get a fireplace mat, the kind made to set freestanding woodburners on. It would be too large, but you could cut it down & possibly double up to get two layers.
Let us know how you come out.
Last edited by RHarkins; 06-04-2009 at 11:58 AM.