I never have used the Harness that come with the lights. I have always done it exactly like the video shows, minus the box. The only thing I would have done differently with the box since it allows for such a nice neat custom install, is used Relay Blocks that would allow them to be mounted to the side of the box instead of just laying loosely. also when I add a new fusee block, and a relay, I get a fuse box that will allow me to add in several new circuits if I need, at the same time I wire in the same amount of relay connectors as empty fuse slots, so that all I have to do is attach the wires, hook up a switch, and plug in the relay and fuse to make the new circuit run.
Right now I am working on swapping in power doors into my 2000 Ram, taking them out of my 1995 Ram donor truck. Since the wiring isn't comaptable, Instead of splicing into the 2000 Fuse block, I decided it better to go ahead and build me a new accessory power distribution center. I know that I need 3 power circuits to make every thing work, but I also have 2 sets of off-road lights, and a Hydraulic winch that I just kind of through the wiring together on. So while I am at it, I am adding a 12 circuit fuse box and 9 Relay Connectors, I know i won't be using that many relays for a while, but knowing I have that ability should the need arise is just a good piece of mind.