Never seen (excuse pun) minimum level lux/lumen/candela of portable hand held ilumination device specified in any aircraft manufacturers document such as the maintenance planning document or AMM etc. However for your fleet it might be. Have a look! Failing that your Employer may have specified it in the QA or other such manual.
Otherwise the Maglite 2/3 cell was the industry standard and most torches of the LED type are more powerful than the Mag.
There are perhaps two more important questions than yours?
1. Can I illuminate all the items specified in the Daily/line check list (eg: The fan OGVs from the back of the fan exhaust for stone or bird damage)
2. Will it work again when you drop it?
Cos you will.
