Lots of options that people who know more than me will likely recommend. On the budget side the Wowtec A2s would be a good choice with a good firefly mode. I like Thrunite as well. Armytek wizard also has a very low moonlight mode.
Basically I think it comes down to two things. Low moonlight mode (few cheap lights have this) and a good quality cell. HJK battery reviews are probably your best source but hopefully more experienced people will chime in here and make a recommendation. Most of my 18650s put out 2000 mAh or less. It is easy today to get cells that legitimately put out 3500 mAh or so. That alone could nearly double your run time depending on what your current run time is based on.