Re: Hi from Monterey!
Marc, you might want to do a little reading using the search feature for your fuel tank idea. I know others have done it successfully but I don't have those threads at my fingertips right now. Maybe someone will offer some suggestions.
As for using the white wire for lights, I usually suggest against it. It will only provide about 3watts of power. That isn't much and any light you get from it will be minimal at best. There have been a few successsful attempts using some fancy electronics but simply carrying a battery is the simplest method. If your lights draw more than 3 watts it will seriously effect the ignition system, even to the point of keeping the engine from running. Again, the search feature will provide you with a wealth of information. Simply type in 'white wire and lights' and you'll have plenty to read on the subject.
Good luck. Have fun and ride safe.
Age and Treachery Will Always Triumph
Over Youth and Skill & "Charlie Don't Ride"