I use the Platinum Series 60/55w H4 lamp. There is another version that has a higher power rating, but i did not want any complicaton with my wiring. These lamps are bright enough anyway, much brighter than the stock Osrams that came with my Eurolamps.
though you don't ask for it, i would also recommend their amber foglamp - the H3 Ion Crystal lamp. It really makes a big difference.