Best drop-in option is halogen infrared refraction (HIR) bulbs. 9011 and 9012 can be easily modified to fit in 9005 and 9006 capsules.

Here's some information about how they work:
HIR Headlights 9011 9012 bulbs


Here's where I bought mine from (high beams only for the 97-03 projectors):
HIR Bulbs - (HIR1) and (HIR2)