hey guys I'm about to build a new PC rig and I'm want to know which are the best aspect to run Zbrush and Keyshot you know wich motherboard, the best processor, how much RAM, HDD and over all if I must buy two Radeon 480 in Crossfire or just One Nvidia GTX 1080

PS. im also develope games in Unreal 4 and use the substance suite what do you think?