a machine learning pc

Good morning, I spent some time thinking about buying a pc to be able to perform my experiments with machine learning also to play games like Star Citizen at full max with support for RV, Occulus or Vive.

I was thinking of mounting something with an SLI with two or three 1080's, can you make a three card sli? I do not know which cpu could be the right one, I wish it had at least 32 or 64 GB of ram, but of that type, DDR4? Is there any faster memory in the future that is worth waiting for? What motherboard? I imagine that cooling this monster will not be simple, I also wanted to know if there is any flavor of linux able to support a SLI configuration, because to experience boot Linux and when you want to play would go with win10.

Then the theme of the monitor, with that configuration, some capable of showing decent 4k.

Do not cut yourself with the price, but I would like to see alternatives.

Thank you very much for the help.