[dominicperry]

One thing to watch out for - the "higher" specs - Cat 7 and Cat 8 - often have huge boots round the connectors, which can be a problem with some machines and switches/routers - there just isn't space to plug stuff in. For example, the two 10Gb/s Ethernet ports on a Mac Pro 2019 are really close together and a huge boot makes it hard to plug two things in next to each other.

All of which points to just buying a standard Cat 6 cable.

I'd recommend buying a branded cable - there's loads of rubbish on eBay that isn't really compliant with standards. Get one from a reputed local chain store (in the UK, that's PC World).

Dominic