The stock lamps are D3S lamps.
There are upgrades- Philips XV2 (Xtra Vision 2), Osram Xenarc CBB (cool blue boost), and Osram Xenarc Nightbreaker Laser all claim to put out more light at the same 35W power level as stock.
I listed them from cheapest to most expensive. There are a couple comparisons on Youtube where they take lux readings.
The CBBs are nowhere near the 7000K they advertise, just a bit whiter than the other two actually. The Xenarc Lasers are crazy expensive, but have tested to output the most lux on low beam. (No actual lasers involved, other than in manufacturing for the record).
I think I'm going to put in the CBBs at some point to match the LED running light a little closer.