As Pat mentioned,I have the Advance wiring harness in my car. The system is quite modern using six relays and eight fuses. The materials are first rate and the instructions very thorough. The relays are generic Bosch style available at any parts store.
That said, the installation process can be intimidating. What you get is a Power Block (as shown in one of the pics below) with a ton of wires attached in several bundles. It's up to you where you want to locate the block, and how you want to run the wires. It's a time consuming installation, but if you're not into originality and want a good wiring set-up, this is about as good as it gets.
BTW, Pat's doing a fine job with his. He's taking his time and he'll have a good, reliable system when he's done.
Edit: Also, Advance has the instruction booklet online if you'd like to see more of what it's all about.