Well if you are asking if corals will limit the kinds of fish you can have, a lot more research is in your near future. If you have corals, you will have to stay away from most angels, buterflyfishes, groupers, triggers, and puffers to name a few. Clownfish, royal grammas, gobies, and damsels are all ok though. Im sure you can see why so many people do FOWLR tanks, because im giving up owning all my favorite fish [besides royal gammas] for the corals. But if you do both, you can add 1 maybe 2 small fish at one time every 1-2 weeks depending on the size, to prevent to biload from becoming too big all at once. Then wait a while until the tank has become more stable with fish, then you can add corals. Mushrooms are a good starting point. They come in neat colors and patterns, and are low maintenance and can multiply quickly. But first, add some hermit crabs and snails for cleanup if you havent already.