They are a complete unit ready to go. Not a DIY. I bought mine from ebay. Name of the store is "peaktop outdoor". They are now $176.89, but that also include free shipping. One thing to note, you can not adjust intensity, they are either on or off. For me this has not been a problem, but just wanted to let you know. I have mine mounted about 8" above tank.
"Epistar New 120 Watt Led Aquarium Grow Light Blue White Coral Reef Tank Black"
http://www.ebay.com/itm/Epistar-New-...item256ca62201
This is the one I bought