Here's for those who want to get some replacements for the Oculus Rift:
https://www.oculus.com/accessories/
https://www.oculus.com/accessories/
For what it's worth, the cable that comes with the Rift is already 4 meters long, and the replacement isn't an extension. If you need more cable length — I know I certainly do — then extension cables from Amazon or similar would probably work.
In that case I'm an idiot. I thought the original one was 3m.
Oh well, I may swap it out anyhow as mine's quite badly kinked near the HMD end.
I do have 6 inch or so HDMI/USB extensions to make it easier/quicker to plug in due to my cramped tower placement. I keep meaning to buy some longer ones but I can't seem to find any solid information on which ones work apart from a few from the states.
if i remember when i get home i will let you know which ones i used. it took a bit of faffing but mine finally works as it should, with 2m extensions for the hmd and 5m extensions for the sensors.
edit
for the sensors
https://www.amazon.co.uk/gp/product/B0179MXKU8/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
hdmi for HMD
https://www.amazon.co.uk/gp/product/B01D5H90L4/ref=oh_aui_detailpage_o03_s01?ie=UTF8&psc=1
usb for the HMD
https://www.amazon.co.uk/gp/product/B00TCMGM5E/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
note the usb for the hmd does work for me, but i would probably buy a better one TBH if i was doing it again, the amazon basics one seems a little better quality..... but my amazon basic cables i have are too long.