Wow, thank you all very much for your advice. :yh:
paul1598419: thanks for recommending the battery site. Hadn't heard about them!
Gazen and Alaskan: those PL-E models from JetLasers look fantastic. Thanks for the advice. What's the real difference between the Mini and the Pro? I see that the Pro has a larger Working Temperature range, which might be helpful for us, but am not sure what the other real differences are (other than dimensions/weight and a slight difference in Beam Diameter). Do you know if the Challenger II from Sanwu is less temperature sensitive than those PL-E models?
Thanks again, everyone.