Hi there!
interesting thread so far. I must admit, I am a very lazy bum, so I usually opt for constant current drivers instead of resistors.
Constant current drivers are quite expensive, but somehow "fire and forget"..
..just add it and forget about power settings (and -a nice side effect- also forget about power surge or fading leds when the motor is pulling to many amps etc.)
Here's my source (of both leds and drivers):
Constant Current Driver
Btw. I recently bought both the lightning starter kit and a pico switch from Dimension Engineering. Absolutely fantastic stuff!!!
I will be
using the starter kit for a light bar
..and the
Pico Switch (no need for the battle switch) to switch a siren.
Cheers
Pip