I picked your parts to start expensive.
Expected 188Mh/s after Biosmod @ 850 Watts
You will need 6 of these GPU's for your expensive rig.
You will need 6 GPU risers for your rig.
An SSD will be better for miners.
We go for maximum efficiency here.
6 or 7 GPU Motherboard
A fast LGA1150/1151
4GB is enough, 2 at once is cheapest.
A power button to turn it on!
You could always make your own!
The current Cheapest Components for your Rig.