There is a great deal of information on automotive lighting up at this site:
Daniel Stern Lighting Consultancy and Supply
In the tech section of the site, there is quite a write up on "Blue" replacement bulbs, and comments on HID's.
I run many of his products to good effect without blinding oncoming traffic.
He just directed me to another supplier for upgrades to my 9005 and 9006 bulbs. Same power, same bulb life as stock, more usable light. They are correct for the stock reflectors and lenses in my daily driver.
He also has upgrade schematics on the site for automotive lighting circuits.
CJ