Help with 3x bike light

I'm looking to put together a bike light with some left over components. Can someone assist with a basic single light with minimum 2 hours of run time using a Mag D head, tail cap switch and 18680 cells externally mounted.

Here's what I have available:
Mag D head w/ glass lens.
3x 20mm reflectors
Heatsink, I believe it was called the perfect triple (3 stars with center hole).
Taskled - Fatman driver
7.2v LiOn protection circuit

Need suggestions on LED's. I don't need a thrower, probably closer to a flood. Looking at 500-800 lumens. I was also thinking about driving 2 LEDs as flood and the third as a spot. No idea how to do that yet.

I've tried searching, but I can't seem to get a good grip on LED-driver-output combo.

Thanks for your help.
Boris

This thread would likely get more responses in the bicycle forum : http://www.candlepowerforums.com/vb/forumdisplay.php?f=86