Have a look at this thread from BetweenRides. cehowardGS is a "pro" (ok, not really) when it comes to flashlights on bikes too. He loves his Keygos M10's (review here, buy here). I'd say to pair an M10 or two with a Trustfire Flame Protected 26650 and the Trustfire TR-005 charger - both of which have been tested, reviewed, and recommended by benckie here and here.
Hope that helps. BTW - I don't personally own any of these.
-Garry