I have 400 MH and 120 PC on my 120 and my zoos eventually started bleaching. I found that sticking with PCs my zoos looked better. Though my 26Bow was under 150MH at 20K and the zoos did fine in there. I don't think there's a clear cut answer to what works, it can depend on where the corals are placed (high, low, mid) that can be the determining factor. I have a 24 Pod right now with 64 PCs and a 4.5 inch sandbed and I placed my zoos on the rockwork which is about 8 inches from the top of the water and 9.5 inches from the light, they seem to be doing pretty good.
not much of an answer but experiment with placement before spending too many dollars.
good luck