Euro lights are what Mercedes designed the cars to use for the entire world, except as modified by the Feds for North America.
They usually employ an H4 bulb, at least on the w124 chassis. They also are made by Bosch, Hella, and others.
The euros are likely to be superior to the 'H4 conversions you discuss - the euros have a distinctive beam pattern not usually seen on US headlights except in the last couple of years. (ironically, my 98 C230 legal US lights have the same __/ __/ double slant beam pattern that my 'illegal' 87 Euro lights have!)
2003 Firemist Red/grey leather SL 500
2015 Palladium Silver/black mbtex GLK 350
1987 Smoke Silver/burgundy mbtex 300E Sportline (SOLD)
Click to see 87 300E