I would venture to say yes you can do quite well with that lighting depending on the coral......It depends on the types of sps you want to keep. There are so many variables.
I used to have 175W mh and had some pretty reasonable results, so for the most part you should be fine. I would however warn you that if you start growing sps under 175's an upgrade is eventually inevitable as you will start to want the harder to keep species to get more colour. Well maybe that was just me.
