I'd look at the Fenix BC30 v2. I believe signing up for the email list at the bottom of the page gets you a 20% off coupon code.
Battery life: infinite. Just bring as many spare 18650s as you need. I'd get these batteries and this charger if you're in the US. The charger also serves as a USB powerbank and a way to carry spares. Protected, button-top 18650s are recommended for this light.
It does a stable 600 lumens for 6 hours so you might not need spares (but you do need to buy at least a pair of batteries and a charger separately).