I just ordered a set of Strada ush tubeless in a 32mm for road and gravel riding.If you want to shred some gnar, what about something with a flat patch in the middle then knobs on the sides, like a Clement X'Plor or Strada? You definitely don't need knobs for gravel though.
http://clementcycling.com/strada-ush
My frame is only good to 35mm.