Tombstones with the R.I.P. embossed into face. These will print at various sizes, and should need no support (for the solid versiion) or minimal support for the versiion with a decorative opening. I'd attempt to print without supports, as the two sides of the top curve should meet at the middle. 

Adhesion: nothing or a brim or raft, but the bottom is flat so no adhesion might be needed.