This thread is huge so I will go ahead and ask these two questions:

1. Can one rig use two different miners at the same time? For example if I have mixed nVidia and AMD cards on one rig, I'd like to set ccminer to mine lets say ravencoin and the AMD cards to mine ETH. Is this possible?
2. I suppose the rigs would need to have windows installed on them. Is it possible to boot them from USB without the need of a hard drive?