Some serious suggestions.
While I don't know exactly what he will be doing in Afganastan, I would be betting that it would be serious work with the potential for the unexpected to arise any second. I would want powerful and reliable.
If he is not doing hours and hours of walking, I would go for the big guns, and choose the Streamlight SL35X. While rated at 40,000 CP, and the UltraStinger is rated at 75,000, it has a 20 watt light bulb / 100 hour life, as opposed to the UltraStinger's 10 watt, 30 hour bulb. Overall, this sucker puts out the light!
If the weight is too much (2.8 lbs), he can get the SL20X (1.9 lbs) and put a SL35X bulb in the SL20X. It doesn't sound like run time will be a problem, as he will be recharging it in the car. Same amount of light, just a smaller battery, and shorter run time (I confirmed with Streamlight that this combo is an approved combination!)
I would also get one of thes big spotlights, like a 2,000,000 CP hand held rechargable. My favorite is the Optronics. Again, a 40 minute run time, but with a "base" vehicle always nearby, recharges are not a problem.
I would also recommend a smaller light, such as the Stinger, or Stinger HP, for times when he does not need as much light.
Of course many, many backup bulbs!
I would also cary a very small, but long running light as a EDC backup light, should he be away from his vehicle for 5 minutes, and not grab a light, and all of a sudden, need a light.
Also get belt carriers for the lights.
Everyone raves about SureFire (and rightly so!), but many (millions?) of Law Enforcement use Streamlights daily.
The UltraStinger, SL20x, SL35X, Stinger series, and Scorpions are used by law inforcement all over the country.