150w should be sufficient, but if you want some of the harder sps corals, then go larger. I have 150's and house mostly lps, softies, 2 RBTA, (split) and croceas. I place the croceas up higher on the rocks. Your tank is not that deep, so don't over do the halides, you will just get algae out the gazoo.... I have an open brain and plate coral all doing well.