Here is a photo of an LED lightbar that I made. It uses 16 LEDs that are nominally rated at 10 watts (input power). THe power supplies I am using are slightly underdriving the LEDs so the total input power to the 16 LEDs is more like 140 watts. So this is equivalent to about 3 54 watt, 4ft T5 HO lamps.
I am using LEDs instead of fluorescent lamps because I want the tightly focused light source available from LEDs. This enables me to place the lights much higher above the bench than if I were using fluorescent lamps. In this photo I am using optics with a 23 degree beam spread but because the plant bench underneath has been changed to one not nearly as deep I am going to replace those with optics that have a 12 degree beam spread.
Here are the LEDs that I like:
LED Engin