Aaron,
I don't think so - I believe the board you are referring to is a foam product. You need something that can withstand the extreme heat you are going to generate. Forno bravo sells what you need or you can do a google on insblok 19 (and there are other products) - we prefer you buy it from James
If you refer to the plans on this site, it will give you a recommendation of a sand / clay mix for leveling the floor. Good luck and keep the questions coming - we're here to help another brother of the brick.
Les...