Opinions on an attempt to run Skyrim @ 8k Down-sampled to 4K (early stage - build questions)

Hey, thanks for clicking

I will be brief. New build, I need opinions before I start buying.

Usage:

*High res rendering 8K

*Super-sampled Gaming, or is it down-sampled?

Main board: - Asus Crosshair V Formula Z

CPU: - AMD FX 9590 @ 4.7

GPUS: - 2X AMD R9 295X2

Memory: - 32 GB DDR3 @ 1600 9-9-9-24

SSD - 3 X 64 GB in RAID 0 ---- EDIT: +HDD

PSU - 3 X 650W

What am I doing wrong?

What case would you recommend? (Don't want to spend so much on the case)

Thanks for your time!