Halide or PC ?
 

Myself, I think the dimensions of the tank are important. If it is a standard 33 one 150W MH is probably not quite enough because of the length. You can get a 36" Allglass top that is 110w PC. I myself have a 24x18x18 33 gallon tank with one 175w MH pendant with only soft corals and mushrooms, and Polyps. I am currently using an old 5500K Coralife bulb, because my new Xanium H2 bulb became horribly dull in two months of use. To date everything is still doing well. :D