There's M8 (low) profile keycaps that are lower than and slightly thicker than DSA, but they're only available in 1u, 1.5u and 2u (Ergodox anyone? [oh god, I sound like tp4]).
Front to back: M8 low profile (only supports PCB mount stabs, bottoms out on housing), M8, SP DSA
Left to right: SP DSA, M8, M8 Low profile
2u blank M8 sitting w/ rest of granite
Cherry M8 DS, SP DS DSA, Cherry M8 Blank
Has a smoother and "scoop-ier" face