i have an african butterfly, around here you have to preorder 3 at 15 bucks a piece from pets barn. he does not allow anyone on top, he goes over to them and pushes anyone down that comes to the top.
Buttefly fish may end up dat food, look for the giant hatchetfish, triportheus angulatus. they get about 8" long and are beginning to show up in the hobby.
Long finned apollo sharks (Luciosoma spilopleura) would do nicely if you can find them, may be a tad small tank size for them but not too bad i would thin k.