Advice for my rig

Hey, I’m thinking about building ZEC/ETH mining rig. I had a couple questions about my current parts list.

  1. I currently have 8gb of ram, could I get away with 4?
  2. RX 480 sapphire nitro 8gb or PowerColor RED DEVIL Radeon RX 480 8gb? Nitro is $25 more.
  3. Currently have an i3 6100 cpu goes for about $180 cad. Should I get a cheaper cpu or go with this one and be able to possibly do some mining on it?
  4. Lasty could someone recommend a good psu that will have room to add more gpus? If this works well i’ll mostly be upgrading to 5-6 gpu’s.

Thanks! Anyother advice is appreciated.