I’d recommend checking out the Ledlenser MH10 Rechargeable Head Torch. It puts out 600 lumens for 10 hours. 18650 li-ion batteries are easily swappable. I carry 3 batteries on long trips.
They also do a helmet bracket kit. I think I paid £59.99 at Go-outdoors.

I can recommend this. Really strong and sturdy. It is a Fongkong copy of the Quad Lock.
https://www.amazon.co.uk/gp/product/B09 ... UTF8&psc=1