How much light - got an opinion?

[Safedad]

I am upgrading from a 55g to a 90 gal. I have some acros, maxima and crocea clams, monti caps, trumpets, birdsnest, kenya trees, pocillopora, maze brain, zoos, bubble tip anemones... I currently have a 400W 10K mogul MH (will probably replace with 12-14K MH at next cycle), and 3 55W PC (1 50/50, 2 Actinic). I do struggle with heat and am building a new light hood. The hood will have a gap between the tank and sit on legs. I have a pane of tempered glass I just bought to keep the bulbs separated from the water and dry. One got splashed on last year, took a week to find, and burned some corals. I plan on having it open on the top and back. My current tank (got it free, second hand) didn't have a cross member in the center. I made a plexiglas one out of some clear stock I had. The new tank has a black center cross member. I am thinking about two metal halides along with my PC's. I will need to get another ballast, reflector, mogul base. My tank will be in a different, larger room with much better air flow

In general, what do you recommend for MH with a 90 gal and my coral collection? 175, 250, 400 .

P.S. Since the tank is going into another room and they really aren't mobile, I am told we are getting new flooring before the new tank goes in.