As others have said, with a tank that large the aquarium world is your oyster so to speak
Personally, I'd load that tank up with a good mix of large and small fish, to create a more natural looking reef environment and avoid having a tank with a couple massive predators (which actually sounds pretty cool too, come to think of it :lol
. It's ultimately up to, your personal preferences, and how much hands on maintenance you want to perform on a tank this massive. Personally I'd add...
* School of schooling bannerfish (Heniochus diphreutes). They are reef safe, hardy, group together nicely in large systems, and get big FAST!
* Group of Monos (Monodactylus argenteus)
* Group of Stripeys (Microcanthus strigatus)
* Group of Pyramid Butterflies (Hemitaurichthys polylepis)
* Harem of Genicanthus Angels
* Pair of Blue Jaw Triggerfish (Xanthichthys auromarginatus)
* Massive group of Longspine Cardinalfish (Zoramia leptacantha)
* Several fusiliers if you're willing to feed often
* Bluespine Unicorn Tang (Naso unicornis) - The novelty of having an aquatic unicorn cruising around your tank (if it's large enough) never seems to get old
* Dussumieri Tang (Acanthurus dussumieri)
* Loads of damsels for color, movement, and diversity. Avoid the more aggressive genera, and stick with the more benign species
... If you like big groupers and other predators and don't mind having to go in and siphon out waste pretty frequently, you can go that route too. This is just what I'd do with a tank that large. Good luck :beer:
