Compatible psu and pci riser question

Hi there,

I am looking to mine with 6 GTX1070's, for this is will assemble the following system:

- Corsair HX1200i
- G4400
- Asus Z170 PRO GAMING
- 8GB RAM
- 80GB SSD

Since I have yet to order PCI risers I am wondering what kind of these I have to order. Some of them have Molex power connections and some of them have PCI power connections. What is the best one to order? And will this PSU be able to power all 6 cards using cables supplied? If so, would you connect PSU to just the PCI risers or also to the video cards themselves (this seems the most logical but just want to verify it).

Sorry for these nooby questions and thanks in advance for taking your time to read this.