Do your research on LED's. You are gonna get mixed feelings on here regarding LED's. Get the one that is built right, is good for your corals/livestock, and that you can afford.
Good LEDs don't have to be expensive. Rapids were the bare bone fixture with expandable capabilities using the same cree chips as a lot of major brands. All I cab speak from is experience and Rapids are just that. They provide Rapid growth my friend.
A big consideration is what size tank and what corals you want to keep then look for what fixture meets those needs and find a vendor with good reputation that sells that.