Could you post your recommended length for custom cables?
This would be my recommended order from ModDIY if I was going to order again. Please do your own measuring before you order though as I don't want to be responsible when your motherboard or video card connectors are in a different location. You can send them an e-mail with the following and they will respond quickly with a quote. I paid around $110 before shipping for these. These measurements are based on a Biostar X370 GTN and a RX Vega LE.
For Corsair SF600 PSU
Specifiy Color
one piece of 20+4 pin ATX modular cable, 20cm
one piece of 4+4 pin CPU/EPS modular cable, 37cm
two piece of 6+2 pin PCI-e modular cables, 14cm
one piece TM-6P-4xSATA (lengths: 22cm, 13cm, 11cm, 16cm w/ 4-pin fan female pigtail 5cm)