Just an FYI: The painless harnesses dont come with all the connectors needed to just plug in their wiring. Also the fuse box is different. However, if you're gonna be adding alot, doing custom mods...they are great.
If you are just wanting to replace existing wiring with new, then you might want to go with M&H. There site is
www.wiringharness.com They are by far the best for direct replacement and can be ordered with simple mods, such as HEI options and a few others.
I have used both and both are good quality, each one has its benifits.