With a tank as deep as yours I would suggest going with 400w MHs. If you go less then that you will need to get some very good reflectors to project the light. This can be accomplished with the use of Lumenbright reflectors but expect to pay $100 each at the minimum for them.
Large tanks like yours require lots of light to maintain SPS
corals. You will probably need to increase your flow as well. That's a lot of water volume to get moving.
The tank looks very nice though!