I spent some time today ordering parts for the second iteration of the light:
* DC-DC boost converter
* Li-Ion charge/protection PCBs
I've also got a few high quality heatsinks which I may compare to try and figure out which I ought to use, and a reflector and collimating lens.
Ideally, I want to add a switch and a charging port, in addition to upgrading the cell-holder wiring to something that will more comfortably carry that much current. With those things in place, I may be able to start planning things like a case and how to manage heat-transfer if I make this thing weatherproof to any degree.