Purchased item list - missing anything or bad choices?

Six (6) XFX 570 GPUs
Seasonic Flagship PRIME SERIES SSR-1200PD 1200W PLATINUM power supply
ASUS PRIME Z270-P Motherboard
Intel BX80677G3930 7th Gen Celeron (1151)
Crucial 4GB Single DDR4 2133 MT/s RAM
PrimeStar 6-Pack Ver 006 PCI-E Powered 16X to 1X Adapter Riser
Electop 2 Pack 2 Pin SW PC Power Cable on/off

I know I need a case next. But what else am missing? I think i will go USB stick and boot Linux (need to research that now too)....

Feeling a little queasy about it all.