Thanks Frosty,
And I updated my profile as per your recommendation
So it looks like the wool is the way to go; I'll be using a small 1" firebrick as the floor
When hunting for materials today I thought that these duct parts would potentially make a good body: https://www.box.com/s/6nzzjtxkxr9e83g0iy7l
At least, better than a coffee can Iguess; It's 30ga galvanized steel and goes from 8" to 6"
Correct me if I'm wrong; I thought that having it tapper might yield better heat, but that's just a wild guess from myself (I know nothing about this to be honest, but I'll learn!)
What I was thinking of doing it to cap both ends, cut an opening in the 6" cap;
Line the body with ceramic wool (got 8lbs 1" thick) and use a 1" firebrick as the floor.
I'm just not sure how I will line the body with the wool yet, since it's tappered; Looks like I added a level of complexity from day 1 :P
For the caps, is it a good idea to fill them with the mortal listed above? (Spec sheet in english here: http://www.bomix.ca/pdf/pyromix_en.pdf)
Thanks!