You would want this kit here: https://www.amazon.com/CableMod-ModMesh-Sleeved-12VHPWR-Corsair/dp/B0BJ2DD5CQ?ref_=ast_sto_dp&th=1&psc=1
The 3x8 option would work fine all in the same, 2 cables for power, 1 cable for redundancy. The 4x8 is 2 cables for power, 2 cables for redundancy. Will function all in the same though. :)
For the blue label HXi you would want this kit here: https://www.amazon.com/CableMod-ModMesh-Sleeved-12VHPWR-Corsair/dp/B0BJ2DD5CQ?ref_=ast_sto_dp&th=1&psc=1
We have individual 8 pin PCIE cables for your PSU actually. You can find that here: https://www.amazon.com/dp/B08GJNPCB3?th=1
We also have a direct replacement 12VHPWR cable if you want that instead. :)