PSU Cable Sleeve Help

[TeePoint]

https://pcpartpicker.com/user/TeePoint/saved/#view=6gjP6h <<<This is my build.

This is my first build I will be doing. I want everything to look nice. So I'm doing my research as much as possible. My question is, what cables do I need for my particular build to only be showing in my case like the picture below?

Looks like there's the main chord to the motherboard, a chord to the GPU and a chord in the top left corner. Like I said I only want the Cable sleeves to be showing in my case. I don't want a full cable kit for my PSU. I believe they are called cable extensions? Correct me if I'm wrong. I don't really know what I need. I just want my cable sleeves to be showing in my case. Don't care about the cables not showing in the back of the case. Someone please point me in the right direction for what cables I need for my build. Or how to go about this.

Also, how many CMs would I need in length for this particular build? The site I'm using custom makes your cables from size 30 CM to 100 CM in length. The site is https://pexonpcs.co.uk/
Extremely nice cable sleeves hand made. But for a price. Thank you.

 

[raisonjohn]

Since you will only use cable extensions (not full cable replacement kit), you only need the shortest typical available length (say ~30cm) as only a few cms of such extension cable are exposed. All of the stock cable lengths from your RM850X PSU is sufficient to run the cables concealed to a point where the sleeved extensions start to go out from the cable routing holes.

Based on your parts list you linked, you would basically need the following extension cables:

1 set of 24-Pin Extension Cable (connects to your motherboard's 24-pin ATX power, the one at the right side of the mobo)
https://pexonpcs.co.uk/collections/pc-cables/products/24-pin-extension-cable

1 set of 8-Pin EPS Extension Cable (connects to your motherboard's 8-pin EPS/ATX12V power, the one at the upper left)
https://pexonpcs.co.uk/collections/pc-cables/products/8-pin-eps-extension-cable

1 set of 6-Pin PCI-e Extension Cable (connects to your GTX 1080 GPU's 6-pin socket)
https://pexonpcs.co.uk/collections/pc-cables/products/6-pin-pci-e-extension-cable

1 set of 8-Pin PCI-e Extension Cable (connects to your GTX 1080 GPU's 8-pin socket)
https://pexonpcs.co.uk/collections/pc-cables/products/8-pin-pci-e-extension-cable

Just choose the pattern and colors that you like.