I am in the initial stage of my fire pit project - planning. After looking at a bunch of designs, I am leaning toward a 3' x 5' (10 in thick) concrete rectangle. I am modeling my fire pit off of a design I saw that was a concrete square pit with a fire bowl inside. I essentially want to do the same but the rectangle pit doesn't really work with a fire bowl. I've been trying to determine if I can find prebuilt fire "boxes" roughly 2' x 4'.
Design: 3' x 5' Rectangle Concrete Pit filled with a base of gravel/sand, Fire "Box" on gravel, Empty space around box filled with gravel/sand until near to the top then filled with nice river stone
Should I go the route of using a fire "box" with concrete rectangle pit, line the pit with fire brick, or scrap the rectangle idea altogether for a different design?