I have been using the Shunyata Sigma USB or about 5 years now. I have not found any cable that bettered it. I am curious about the Snake River Boomslang USB. As far as ethernet, I should probably look to more research, but grabbed an Avanti here and run it through an ADD-PWR I/O unit.
If the Shunyata ethernet is as good as the USB it might be a winner.