Galax or KFA2 GTX 1070 has 1x8 and 1x6 pins PCIe.
http://hardwareoverclock.com/KFA2-GeForce-GTX-1070-EX-OC.htm
KFA2 or Galax delivers solid hardware, I have been using their products since GTX970 EXOC (2 of them on SLI).
Now, I have the GTX1080 EXOC.
Th cons of their EXOC cards are that you need to manually fine tune the fan curve yourself (the stick settings is not nice) and you can not completely disable the fan for lower temp. The fan is still very silent even on active.
I have not OCed my GTX1080 EXOC since I do not need the extra OC yet, the factory OC is still enough.
I OCed my GTX970s to the brimps, I can reach stable 1625MHz core and 8GHz VRAM with max 75'C in 24'C room temp, for both GTX970 EXOCs. I guess I was among those...