Man! I'm looking at some of these lights and thinking "Those are expensive!"
At my local Menards I've been buying off the shelf 4' LED "shop" lights when they are on sale for around $15 each, those are the cheap ones and some are over 4 years old now. They come with a cord and on/off pull switch, and a female receiver plug on the other end from the cord so you can plug up to 6 units into the same outlet. Some of mine are wired through the wall switch (using the wiring from the fluorescent fixtures the LEDs replaced), and some I turn on as needed with the pull chain. You get the hanging chain kit as well. I've been replacing each 8' florescent fixture with one 4' LED each time I can pick one or two units up. The stock varies, sometimes there are not many there, other times the rack is full. I suspect the more expensive LED fixtures may be better, but the cheap ones have been working well for me.
You want to watch how many lumens the light puts off, 3,000 -5,000 Lumens is brighter then any 8' florescent ever thought of being and work extremely good with my 8' ceiling in my garage. For comparison, the guy at Menards told me a 1000 lumens LED daylight bulb is about equal to a 100 watt daylight bulb, and the brightest florescent fixture I've seen was 1750 lumens. I can't imagine how bright a 20,000 lumens LED light would be. Gene