Evga Supernova 1300 G2 extra cables

Does anyone know where i can get extra dual 6+2 pin pci power cables for this psu.

i need it since the new rx 500 serie Nitro cards need a 6 and 8 pin power connector
and my psu came with 2 of theese cables and 4 singles and i want it to power 6x rx 580