Buy a QUALITY H6M HID conversion kit. They're kinda hard to find, but I just finished doing a conversion on my buddy's bike, and everyone was concerned about them getting too hot. We had an old set of junk plastic lens stock headlights... wired them both up to a 12v power source, and left them on overnight... in the morning, they were still cool to the touch. INSANELY bright... for around 100 bucks (depending on what HID kit you buy) probably the absolute best lighting mod for the money.
Xentec's are actually very good kits for an off the shelf brand. Go with a color temp of around 5000k, the lower the kelvin temp, the more VISIBILE light, the human eye can see, but also the more yellow. We tried a 5000k, and a 6000k kit. the 5000k was still white as white could be, the 6000k had about the same light output as the 5000k, with more of a bluish tint. There are guys in our group that we go with that run those xentec kits on anything from raptors, 450's, teryx's, RZR's.... Anything, you name it. I think out of the 12-20 Xentec kits that are out there, MAYBE 1 person has had issues in the last two years. Good luck! PM me if you want some more info.