Not sure if your cycle is complete so it is indeed a gamble, especially for the sun coral. They fall under the classification of non-synthetic coral, meaning to say they derive most of their nutrition from feeding. And so comes the questions of balancing water quality & heavier feeding to sustain the coral. One might therefore find them in more established systems.
why not stick to photosynthetic corals at the start, once you stabilize your system & get more reefing experience, progress to livestock with more specialized care needs?
some starter livestock include GSP, regular zoas, photosynthetic gorgonians, leathers