Lighting a 180 gallon (60x30x23)

[Tigé21v]

Getting ready to set up a 180 gallon (60x30x23 deep). The tank is eurobraced, with two 18"x19" openings centered.
Tank will be mixed, with emphasis on SPS and LPS. I plan on running 2 MH's, with VHO actinic supplement.
I am debating on what watt MH to go with, as well as the best reflectors for my set up.
Should I stick with 250 watt MH, or step up to 400 watt?
Would I be better to get reflectors which will spread the light more evenly over a larger area, giving more even, though lower par readings. Or ones which will focus more of the light through the openings, giving me two spots with more intense lighting?
I still have not decided how I want to arrange the rock, but I've been thinking of doing two "islands" directly under the MH's.