heat riser material question

I'm beginning to build a rocket stove. I've seen several ideas about what to build the heat riser out of. I know double wall insulated pipe (metalbestos chimney)
only has a temp limit of about 1500 degrees F and this section of the burn chamber should take twice that. I'm making an 8" system.
I'm thinking of using 10" metalbestos pipe and inserting 8" diameter x 3/16" thick steel pipe inside with a small air space between them.
That way I get the simplicity of the pre-made insulated pipe with the protection from the thick pipe.
Has anyone done this?
Does this sound feasible and worth the effort?

Thanks!

Metal is doomed!

I second Satamax: Metal is doomed. You need a refractory type material to stand up to the heat from an 8".

thanks!
I have since done more research and have concluded that the whole burn chamber and heat riser will be firebrick.
I am a licensed sheet metal guy, and I plan to document the whole project, in hopes that I can build them for other people too.
I will post the photos here, in case anyone is interested.
I tore out the old wood stove today, so let the rocket fun begin!

will be fun to see. good luck with the project.