I mod'ed one of these, and boy, can it throw: http://www.fasttech.com/products/1601/10001837/1133700-ultrafire-zb-006-cree-xp-e-r5-3-mode-345-lumen-led. It's probably still available under different names elsewhere. It's small and lightweight for an 18650 light, but probably not as small as what you want. It's featured here: https://budgetlightforum.com/t/-/20642, does 48 kcd.