With the EVGA 1300W you might run into the issue that you have only 2 x 8+8(6+2) and 4 x 8 connector, some 1070 GPU's need 6+8 connected to power on
Not even my Gigawatt GTX 1080 models with the 180 watt TDP need 2 connectors - and since the PCI-E spec states 75 watts from the bus + 150 watts from a 8-pin connector, I'd really like to know why anyone would put 2 connectors on ANY GTX 1070. That would be a 50% increase over the "base" TDP the GTX 1070 was designed for after all.
GTX 1080 I could see it for a card with a very high factory overclock perhaps (but I've not SEEN such a card to date), and the base GTX 1080ti needs 2.
The cabling on the EVGA G2 1300 is heavy-duty enough you could pick up an extra cable set and use dual-connector cables in all 6 of the "VGA" ports on the PS safely.
I don't know offhand if Seasonic sells extra cables, but EVGA has them listed on their website or forums somewhere (but they only sell "complete" cable sets, not individual cables).
I have an MSI GTX 1070 Gaming Z and it requires an 8 pin + 6 pin.
What is the default TDP on those cards?
That power connection setup seems WAY overkill for a 1070.
(Not disbelieving it exists, since 2 of you posted enough reference info I could look it up on MSI's page).
https://www.evga.com/products/productlist.aspx?type=10&family=Power+Supplies&chipset=Power+Supply+Cable+Set+(Individually+Sleeved)
Might be cheaper to grab a pair of the "$29.95" cable sets from that page, they have 2 of the dual 6+2 cables in each set.
I am mining ZEC using EWBF with 65% TDP and it is drawing 145-150W. Gets 480 sols and sits around 47-48 degrees.