You need to find out how big the fish you are going to buy will get when full grown before you buy them. Every fish you listed would never fit by them self in a tank that size. Alot of people make the same mistake. Remember the best rule of thumb is 1 in per 5 gals full grown, now if you are plaining to upgrade to a large tank very soon you might be able to keep the lion for a short time. Sorry for the bad news, Good Luck