Thank you for all the informations !
I wasn't stopped on one specific seller or brand so far and obviously 860W from EVGA seems to be the one to go with. Unless the Corsair Link is really useful ?
The build is already on it's way and i kept about 250€ for the PSU and delivery cause it's a pretty important piece of a rig, i want it strong enough to power it up and secure enough to last so only going with good brands, even if a bit more expensive at first, it's better on the long term.
Thank you for the links too, at first i thought of getting them out of Amazon or materiel.net (bad experience with cdiscount and rueducommerce) but it's pretty good price there !
Also another question, the pc will be running almost 24/7, as this one is, is it more important to give it the price of a platinum vs a gold one ? Just thought about it