Making a VR \ AR development out of old Servers with GTX GPUs

Hello guys, I am new at this and I am in the phase of Buying the hardware for the development.
To keep in mind that I am a “one-mans-band” and I would like to have the best Bang for the Buck possible, hardware wise, to develop VR \ AR games and graphic integrations to real world.

Has anyone have built his/her system based of a old server (like this - )

It says I can put 2 GTX 1080 to this model. But the old architecture of the CPUs and DDR3 is good for VR? (arch Viz and Photorealistic modeling work - people and objects)
I am a noob, if someone could help me. I am lost in this overwelming world of computing options.