Thanks for your answer.
So, for changing the hotend, which voltage is better ? 12V or 24V ? Do I need to change the PSU to 24V ? Is there parameters to change in the configs files ?
In fact my problem is this one :
I live in Switzerland. For a 30£ purchase at RRP , there is an expensive shipping and again 20£ for customs via UPS.
So, I would like to find other resellers - on France maybe - so I can buy parts with less shipping taxes and without customs.
But the Fisher seems to diverge from standards.