Not sure about puffers, but there are some triggers that are "with caution" that you could try corals with - the blue throated trigger and pink-tailed trigger are two that come to mind. I believe some people even consider the blue throat to be the only reef safe trigger. If you do try corals with the triggers, maybe try an aggressive coral - a few sites that list fish as "with caution" note that they might be okay with only the most "noxious" corals.