Build First Rig

Hi to everybody i'm starting to build my first rig, also for fun not only for eth money payback.

Atm i define this config:

Pentium G4560
MSI Z170A GAMING PRO CARBON
Kingston 8GB DDR4
ssd 120gb (M2 interface)
7x SAPPHIRE NITRO RADEON RX 470 8G

Now i have problem to definre PSU, atm for 7 gpu i think corsair hx1000i (1000 watt) should be good (for 200€)

Some people said z170a carbon can also drive 8 gpu (i don't know how if have only 7 pcie) then i need bit more power i think corsair HX1200i (1200 watt) should be fine (for 250€).

What do you think is it ok to start? (i wanna also try to start to use ethos, yes i know i need first to custum bios on win)

Somebody have idea how much watt it can get it?


Thanks for any reply.