Nice! I'll be setting up almost the exact same rig with the MSI Z170a Gaming M5 mobo.

Rig1
7 XFX  RX 570s
2 750W EVGA PSU's

Rig 2
5 Sapphire Nitro 470s
1 Red Devil 570
1200W (hopefully enough power after flashing), otherwise have a 1300w on backorder

Two questions:

How did you connect your two PSU's together? I ordered a ATX with molex coupling board, but didn't realize the EVGA's don't come with molex connectors.

And are you using the SATA to Molex adapters for the riders? Keep reading that it should be 4pin to molex, but again, the PSU doesn't come with those.