Jerimoth,
I have been searching for a good HID headlamp for quite sometimes. I might be able to tell what I found. By the way, I also have X990.
For non-headlamp HID for SAR task, I don't think LC-100 is one of the option due to its fragile lamp bulb. You need something tough, bang and bump is inevitable in the mountain.
I have considered seriously between niterider and edision. Niterider doesn't have good name on its reliability. I have Xtreme LED headlamp from Lupine and love its quality, thus I am a little bias toward Edison. Its flood reflector does put me on a second thought. It was designed to be used on biking that flood beam is preferable but not exactly good for SAR.
Cut it short, I couldn't be able to get an idea HID headlamp for my purpose. Until a better HID headlamp is introduced in the market, I would highly suggest X990. I always carry X990 to the mountain or night hiking, I don't feel its weight. Being fair, 6 lbs is light for a SAR light or for a backpacker. It also comes with spare battery (2 batteries lasts for 150 minutes). Lastly, it's BRIGHT, MUCH brighter than Edison or Niterider.
Regarding Stadium 3, I couldn't see how to carry it unless you want to build something by yourself to make Stadium 3 carriable. Headband mounting might not be an option as it's too big to be a headlamp.
Alan