We are pouring a raised firepit which will be a 14' circle with a 4' insert. We are using Rosetta Stone for the firepit. Stamped concrete for the pad.

The edge of the pad at it's tallest is about 16". We will landscape where we can but the edge around the sidewalk could be a trip hazard. I am concerned about the drop off. If we put a wall on top of the concrete pad, the materials will be different and encroach on an already tight space. They are going to rake the thick edge of the concrete but what material should we use to build the wall so it will blend. Any ideas would be appreciated. Should we be concerned about the elevation?