Some kind of multi mode driver (with strobe).
You should also plan on a 12 volt car charger.
I'm adamantly in favor of an on/off switch and a pot to adjust light level.
That way you can decide what level you want *before* turning it on and also go from dimmest to brightest in way less than a second.
Very handy for getting the right amount of light on something in an instant.
I've used such a setup as a firefighter, mostly with medical and traffic situations.
It also is a lot of fun when you start on dim and they tell you that, ho-hum, it's a nice light.
Then you light up the entire scene and their beams can't be seen anymore.
(And thats with "ancient" early Luxions.)