I suggest you get your email address on the Malkoff mailing list, and try for a Quad Q5. It's a serious monster. 4x Q5 emitters, each on their own regulated driver circuit. The current output is 1150ma per LED on 4-6 D cells. It requires 3.8 volts for regulated operation and the maximum input is 9 volts. The current draw is approximately 2700ma on 6 volts. Stick 2x AW C Li-Ions, or a Kai 2*D Li-Ion pack, or 2x A123 or Emoli cells into that 3D, with appropriate spacers, and you'll have a very bright light!