Upgrading lighting

[Robw]

I am planning on upgrading my lighting from 4 36" vho bulbs to 2-250w MH bulbs. This is over a 50 gallon tank. I currently have mushrooms, a montipora digitata, toadstool, open brain and a LTA with 2 clown fish. I want to start keeping a T. Maxima clam and more sps corals. I also plan on getting a chiller so I won't have any heat issues. Is this too much light for a tank of this size? Any recommendations?