When I had stock US headlights on my 124 I was running Piaa Extreme White bulbs (h3) that drew 85 watts and simulated 135, those bulbs were VERY nice. They weren't really blue, just bright white. They put out more than the headlights (I had also removed the yellow glass cover for the fogs). The lights did not irritate oncoming drivers what-so-ever. And although I had many warnings about how my wires were going to melt, they didn't cause any damage, not even a blown fuse! I had them on my car for over year...then I got Euro 500e lights.
I am not sure about 100wat bulbs, but the 85 watts ones worked very well. I think I even have a picture somewhere and I'll try and post it if/when I find it.