HID help!
GET AC BALLAST, you probably won't need a relay harness but it couldn't hurt to have it, the harness really is more for if you go with a 50-55 watt ballast.
See this video, it's pretty damn accurate.
I had one of the "cheap" full size (like the JLM labeled one in the video) and it flickered but I just got the one in the attached picture from amazon and I don't see any flicker in it.

