Bulb >> 90/100W Narva or Philips Rally:
Lamp Housing >> Cibie H4 E code headlamps
Two years running, never a burn out or filament vibration break.
Purchased my supplies, Lights / Bulbs / Relays / Harness from
Daniel Stern Lighting Consultancy and Supply
after recommendations from members and reading the many write ups / reviews
on his products / services on THIS FORUM. (try a search for many articles)
The bulbs I'm using run @ $20.59 ea, but TWO YEARS, That's just penneys.