I’m not trying to build smokeless necessarily. Mostly, the rocks are for even heat distribution and appearance. I worry that the rings i bought won’t support flagstone, so it needs to look good without them

Either is fine, I’m trying not to break the bank on it though. The pit will be outside, below a high canopy but not covered/roofed. I’m also not sure where I’d even find some of the more esoteric rocks. Would chipped marble work here?