A company I've done business with in the past has some motorcycle-special bulbs and headlights as well as a very good selection of regular bulbs and almost no gimmicky bulbs, all at fair pricing.

CANDLEPOWER has rough service H4 headlight bulbs as well as standard headlight bulbs, high-output standard-wattage bulbs, and high wattage bulbs.  They also have extra bright turnsignal and tail light bulbs.  Our standard headlight bulbs are H4 60 watt hi & 55 watt low.  Increasing to 70/65 watts is probably OK regarding melting the wiring or bulb socket, but any higher wattage probably requires heavier wiring with a relay.  The high output 60/55 watt bulbs get their higher light output due to more precise filament placement in the bulb and higher quality/higher cost gases inside the bulb.  I've used them a lot and like them a lot.

I'm trying a yellow headlight bulb.  It might make the bike stand out and be seen better by drivers...if I don't get ticketed for a colored headlight.  White, blue, and purple headlights are everywhere and don't stand out any more.