Either MH or led will work great as far as your corals are concerned. Even t5 will work if you use enough bulbs. It's about your up front cost, bulb replacement cost, electricity cost (including lights, chiller... if you need one, and MH can create that need, and home A/C cost) and what look you want in the tank. The corals really do give a rats butt as long as they get enough photons of light energy. My only words of advise is if you go leds, and I would, don't over spend on 'extras' you don't need (like 8 channel control, or fancy computer hooks up to do sunrise or sunsets). The almost basic Chinese fixtures do just fine and can cost 20%-30% of what the expensive units cost.
I have 4 tanks. Three were MH & t5 and one was just t5. I switched to all leds back in December of 2012. The only thing that I don't like about leds (and it isn't that big a deal to me) is the 'high contrast' look. MH and t5 bounce a lot of light all over the place in your tank and get a bit more light into the shadows under rock and coral ledges. But leds are more focused and the light comes straight down from above. That makes for more very bright tops and very dark shadows underneath any ledges or large coral colonies.
