Martini:
First off...Please no all caps. This is considered shouting.,
Second the lion.
What type of lion? i take it you mean a P Volitans lion? I say this becuz this fish will grow to over 12" in one year. They are great fish, but they will totally limit any other critter you add to the tank. Remember that this lion will out grow many fish, and ANY fish or moving invert that fits into its cavernous mouth is FOOD.
Yes you can have a couple of these lionfish, just make sure they are similar sizes as big lions will easily eat small lionfish.
So can you have a tank w/ a lion...SURE...but beware that the lion will limit your other fish.
I call small bright colored fish =lionfish food.
An alternative to a large form lion is dwarf species. While not as showy, they do act like lions.
frank