as a trigger gets older its scales become almost like armor against the lionfish's spins, it is very rare for it to happen, maybe in a 90 you could get a harlequin tusk, some kind of puffer, large yellow or purple tang, a grouper??
about the eel, just make sure you have the tank sealed off completly because eels are escape artists and will find anyone hole and jump out of the tank, some believe this is because they hate being in the tank, but my theory is this; they have awful eye sight and chase their "food" out of the tank, or see sone kind of opening and mistake it for somthing else and end up out of the tank.