[jcxr]

WARNING, beware of using old secondhand firbricks that have come out of foundries, chimney stacks etc that may have been melting toxic metals, chemicals etc. Could prove fatal.
If you want the best info, go to Forno bravo website, plenty of ideas and its a forum like AFF.
Or, you could give me a PM and I can run you through it.
I have been in the firebrick/refractory business for 30 years and can supply all you need, or put you onto an interstate supplier near you. I have helped 100's of people build WFO's, both domestic and commercial applications.
I have supplied most brick companies with their refractory materials, and have supplied Clayworks in Dandenong with their materials. They dont brick their domes, they are cast out of high temp , 1350C grade " concrete".
Rendering the outside is easy and you use an oxide to get any colour you want. Insulation is the key factor in building the oven, keep the heat IN the oven, not heating up the supporting structure and the outside enviroment.