Insulation for cabinit build ?

[SmokinHawgBBQ]

I finished my 120 gallon bottom feed smoker and want to build something different so decided on a cabinit build, I have enough stuff hanging around to build it without buying anything but insulation, but to be able to fit chafing pans inside I can only use 1 inch insulation in the cook chamber area, I can use 2 inch for the firebox area no problem. I was wondering if anybody has used 1 inch, and was it enough. All I will have to buy is the insulation which I can get locally in both widths.
Mike