Whats happened with GigE, there were a couple of people looking at this at one time but it went quiet? SDI is still the industry standard for long cable runs and the safe option. NDI is very accessible using a smartphone and a good option for some situations and HDMI cameras for shorter cable runs. USB webcam the best choice for low cost short cable run with zero latency. But camera choices have always been tricky mainly due to the cost (body + lens + interface) but also there will never be a solution which works for all situations. One interesting option are the low cost Zoom Q2n cameras because of the high quality built-in mic (if you want audio), more suited to short cable runs but capable (video and audio). Again it depends on your use case.