School me on MH lights

I think i may do MH lights on my 40b when i move. It has a canopy so what set up would work on a tank like. I do like more blue look of the lights to.

im cureently running 2x 250 watt reeflux 20k lamps so far i really like em! not sure on what the best reflector would be for that setup

The woman has a 40 breeder, and I just put a halide over it. How tall is the hood? What do you plan on keeping in it. I put a lumenarc de reflecter, pheonix 250 de bulb, and electronic ballast over it. She is getting a par of 90 in the corners on sandbed with light 15" off water to bottom of reflecter.