I am starting a new build. It's a 5ft propane with a 24" diameter. The Firefox is going to be 24-24-18deep . I have a couple questions on where the door should go , the Firefox air intake ,and where should the stack go? I ran some numbers on the calculator. It's going to have 4" chimney that should be 41 " . Is it better to put the chimney right on top or should it go on the side grate level? The fb to cc suppose to have a 83 cubic in opening . Will 16-7 half moon work?