When I did my first full vehicle harness, I discovered that I could buy a 200' spool of each of the colors I needed and a fuse block for the price of one of the wiring kits. Now 4-5 vehicles later I still have some of that wire.
If you are planning to do more than one, I would recommend buying bulk wire (I get mine from Waytek) and making it yourself. If you are only ever going to do this one truck, then the added labor might not be worth having the extra wire.
I also like doing it myself so I can route everything exactly where I want it and have every wire be exactly the right length.
