Ethernet

As said get a blue Jeans cat6 cable. They are certified, that is really all you care about. A lot of cheap cables are not terminated properly. I used to make my own cables, still have the stock and tools. It takes a lot of practice to get all the little wires correct. 

If you are going to order a cable, get one from a computer store, get a name brand, like Belkin, or something. They will not be "cheap" but also not expensive. A 6ft cat6 cable should be around $20.

@mikhailark I happen to know exactly what Amazon uses in their DC's for cables. The same cables almost every company used, just Belkin. To the top of rack switch them fiber from there. 

Fiber optic does not carry any noise. It's just light pulses. Nothing in a computer system has the power to create noise. You can get some distortion in the light with very high magnetism. Usually noting in the DC has that kind of power. You can also bend the cable too much, but when using real glass cable it's lets you know how much of a bend you can put in it. The key to fiber is the SFP at the end, that is what really matters with fiber.

The way Ethernet packets work, don't see how an expensive cable will really work any better. The key is to have a certified cable, that is properly attached to the ends. Packets are not all sent in the proper order some are sent more than once. They are compiled on the end, the end unit sends back packets saying it got the packet, the percent it received. It's not a constant stream, but a ton of small hand shakes, packet sent, packets received, etc.. It's all digital, every hop it goes through along the way, the packets are resent from that device. Each hop is decoupled from the previous device. Any "noise" or anything is really only in the final hop to the end point. If there is anything wrong with the packet after it is received, it will be sent again.