Ijones:
Are you familiar with li-ion batteries, their dangers and proper procedures for caring for them?
Are you aware of airline safety regulations regarding the transportation of li-ion batteries?
If you are willing to put up with hassles of dealing with li-ion batteries, then that opens up a world of shopping choices.
However, for simplicity’s sake while on vacation, you might want to focus on AA, AAA, and CR123A flashlights.