Those 100w LEDs are pretty inexpensive, about $4-6 each on ebay. You can also get the glass lens and holder there as well.
http://www.ebay.com/itm/121320571337?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT
I bought one last year to play around with, and it put out an amazing amount of light, at least until the cheap boost regulator I was using burned up and let out its electronic soul. The problem I ran into was that the lens emits light over a 60-80 degree beam angle, which makes it a very wide beam for most "flashlight" or automotive uses. You could possibly put a Fresnel lens in front to focus the beam, but I didn't have time to try this.
Each LED is rated at 9000lm, but I've read they actually put out something closer to 7000lm which is still incredibly bright. Assuming you use a high efficiency boost regulator (ex ~90%) these draw about 8.3A @ 12v per LED.
- Matt