It is easy to open the headlight and bolt in the MH1 projectors from theretrofitsource. There is a major difference between a 9006 HID bulb in the stock reflector and a H1 HID in the MH1 projectors mounted in the factory headlight as far as beam pattern goes.
9006 HID bulbs in stock housing (notice light everywhere, including other driver's eyes):
H1 HID bulb in morimoto MH1 projector (in my 2500HD but the output is the same; passenger side is too high and was adjusted later):
closeup:

the slight mod done to the housing to fit the shroud is visible here. If not done, the projector is angled down as you try to tighten it. Easy mod.

finished look on a stock 100
After trying ebay and ddmtuning hid kits, I will only buy OEM parts or morimoto stuff from theretrofitsource. No affiliation, but the few extra dollars is worth it.
I'd get 35w ballasts, 4500k bulbs for OEM look, mini gatlin gun shrouds, 9006 harness, no led rings, halos or anything else.
https://www.theretrofitsource.com/c...al-kits/bixenon-morimoto-mini-h1-stage-3.html
Follow the install thread and you only have to slightly trim the top edge of the housing to clear the shroud. Not even noticable.
How To: HID+Projector Retrofit on a 100 Series.