We use (and always have) D2S bulbs in our HID kits
In terms of D2S or D2R, Our HID conversion kits use a D2S bulb. We have done various experimentations and for a retrofit application or OE application out side of Europe the D2R bulb is not required. The stripe on the D2R lamps helps hide the salts which would
appear as parasitic images in the light dark transition area of the European Asymmetric dip pattern. On a retrofit or DOT beam pattern (Your headlight), you do not have this light dark transition requirement therefore the D2S bulb is just fine for any application.