I am in the process of changing sugar scoops to Euro H4's. For those I got the OSRAM BILUX 64193 NPB 12V60/55W H4U37R lamps which were highly rated in a German comparison test. I wanted the asymmetric low beam pattern which only comes for the 60/55W lamps.
This, of course, is the asymmetric low beam pattern:
For asymmetric adjustments I found a good instruction:
Daniel Stern Lighting Consultancy and Supply