Did someone say LIONFISH? Someone once said Cranberry and I know a little about them, so here are some answers/clarifications to questions that have come up in this thread:
Lionfish are COMPLETELY reef safe, in that they pay no heed to your corals whatsoever. They will, however eat ornamental crustaceans (with the exception of hermits), and any fish that they feel will fit into their mouths. Based on this, I'd have to say "reef safe with certain limitations on tankmates".
Reef-type triggers and large angels will either kill or harass lionfish to death unless they happen to get nailed in the process. If you want to keep a lion/trigger combo, you'll want to go with a pelagic (planktivorus) species (genera
Xanthichtys, Melicthys, or Odonus). The 120 pretty much limits your choices a bit more...I'd recommend a blue throat trigger (males are the prettiest).
SFE's tend to get pretty aggressive once they get some size on them (20" or so), and altho I kept one for about 15 years, I'd likely not do so again. A zebra would be a better choice, altho they get larger. If you want a smaller eel that can be housed with smaller lions, I'd look into the Golden Dwarf Moray (Gymnothorax melatremus), which max out around a foot or so.
Lionfish actually have the weakest venom of the Scorpaeniformes, and it will hurt if you get popped, but won't kill you unless you're allergic and don't get treated. Also, those long dorsal spines can break off in the wound, so you'll need to watch for that, as if not removed, you can end up with a nasty secondary infection. Hot water immersion (110*F - 114*F, NO HOTTER, as you'll scald yourself) will denature the heat labile proteins in the fish's venom and reduce the pain.
The species of lionfish is dependent upon your tank size, and expertise in some cases, as some fish are easier to keep than others. There really is a lionfish for just about everyone, however. We tend to group them by body size for the most part: small-bodied (Dendrochirus sp.), medium bodied (Pterois mombasse, P. antennata, P.radiata, and P. sphex) and large-bodied (P. volitans, P. russelii, P. miles, P. lunulata, etc). The four top picks for a first lionfish (in order of size) IMHO would be: D. brachypterus (fuzzy dwarf), P. mombassae (Mombasa lionfish), P. russelii (Russel's lionfish), and P. volitans (Common Lionfish).
I'd give our Lionfish Care Guide a read...it will no doubt answer most of your questions, and it also contains some good pix of the various species:
http://www.lionfishlair.com/careguides/lionfish.shtml
Within that article, there's also a link to our weaning article:
http://www.lionfishlair.com/feedingtechniques/toolsofthetrade.shtml
Take a gander at those and come back with any questions they may bring up.
HTH