Mr. D said:
A trigger may rearrange your rocks in the reef. Blue jaws are however the most "reef safe" trigger from my research. Some don't eat snail or hermits, one or the other, or will eat both, depends on the fish. They are usually considered to be one of the least aggressive also but I may still worry with small fish like that.
A fox face is venomous, so you will have to be careful EVERY time you work in your tank but are also good algae eaters.
My favorite of the two is the trigger but I would just air on the side of caution. However, if you have seen vivid aquariums 800gl they have a mated pair and with A LOT of small fish but its still 800gl it's on YouTube if you have not seen it before