fore eye fish r brackesh as they r found breeding nearer the sea so they wud most defantly die wif your arowana i found that they live longer in brakesh condistions anyway i lost alot of them wen they were in stanard freshwater, u sud try some big butterfly fish... or if your worried about drop eye put a ping pong ball in your tank that will flote around n hopefuly make him look upward. butterfly fish r nice anyway 
they arent bony and toxic right? just in case my aro thinks its a snack. i still like the idea of a RC boat or something 