HI,
The kind of lights you select depends on what kind of corals you want to keep.
LEDs are the new rage, but the bulbs are not replaceable...so after the bulbs go the unit is a toss away, but it should last many years before that happens. They burn cool and from reports I have read keep the corals really happy and make the tank look good...but they are super expensive right now, as the new rage usually is. Many of the handy folks are making their own, and I'm sure the folks here would be glad to walk you through a LED light build..
The Metal halide units are finally, after many years at a reasonable price, but they run hot and heat up the tank and you have to have fans to help cool things down, bulbs run around $70.00 each. However they are awesome for keeping corals and anemones very happy. LOL...I have two MH units sitting in my garage.
T5HO is a cheap good alternative....they run cool, the bulbs are inexpensive. However unless you have a shallow tank the light can't penitrate too deep. They are great for soft corals, LPS coral but unless you keep the SPS right at the top they don't work too well for them. You have to really double up on the lights to try and keep an anemone alive. I like the linkable units, that way I could build slow...48" for my 90g cost me $139.00 each...I linked 3 up to keep my reef tank. I have 1 unit over my 56g SH tank, soft corals and macroalgae is all that are in it...the one light is just fine. I had the same 1 unit, over my 30g long tank (it's shallow) I had all kinds of corals thriving under that one light.