Thank you for responses.
The space for the drive can be problem, because I have to put driver inside to body.
TaskLED have interesting choices, LED4power have too, especially LD-B4HV 2-12Amp 2S/4S Multi-Cell driver, but they don’t have in stock now.
Temperature control of the pcb must be, because in Finland we have like –20 degrees cold and the convection not be problem in motion. When I stopped biking the temperature of pcb rises and current must be limited somehow.
If somebody needs work to design boost- or buck driver with temperature control for my bikelight, take contact to me 