XJ,
The wiring for the lights is really simple. I always make a string of wire that ties all the grounds for the 3 lights together and ground it to one spot under the dash (don't ground the lights to the same place as other items on the truck). By harness I mean one long wire that runs to the farthest gauge, and has wires branching off to reach the other two gauges. For the power, run the same kind of harness, and tap it into the headlight switch. For the '03s the correct wire should be orange with a white stripe (orange with a brown stripe on '04). You can see the wiring harness that contains about 5-6 wires coming down from the headlight switch under the dash. It's a good idea to use a test light just to check the wire before tapping (probe the wire, turn the lights on, and move the dimmer). For power just use the test light to find a keyed wire running under the dash and tap into that.
Pre turbo will be much better for accuracy (the shavings won't hurt the turbo... drill & tap and let her fly), and the boost bolt just replaces any of the bolts that hold the intake manifold plate down.
Hope this helps.
John