z800 DUAL X5680 3.33/96GB RAM Dual Quadro 5000.

Hi guys I am new year, I have z800 DUAL X5680 3.33/96GB RAM Dual Quadro 5000 Cards. What can do with this machine to upgrade the 2 Video Cards to whatever is the best for it with two 1080 TI? or anything that is compatible with an LGA 1366 motherboard. I want to learn Unreal Engine on this machine. How is it possible for me to do so? 
Any help is greatly appreciated.