I have a shop in southern maine and I'm putting together one of my showpiece tanks. My big main attraction is a 8 foot diameter saltwater reef shark pond. The one I'm having problems deciding on is a 300 gallon 96"x24x31. The only fish that has to go in there is a black arowana, which is my shop logo. I'm looking for recommendations as to what else would be nice to have in there. I've thought about the smaller rays, peacock bass, tinfoil barbs, Florida gar, shovel nose cat, perhaps an Oscar. What are others experiences? This will be my big fish freshwater tank.