By converting to SDI, you can reliably run cables up to 100 meters for 3G-HD signals and up to 300 meters for SD signals without losing quality.
Standard 3G-SDI converters support up to 1080p60. If you require 4K, you must specifically request a 12G-SDI or 6G-SDI compatible model.
Yes, most modern HDMI to SDI converters feature a Micro-USB power port, allowing them to be powered by standard 5V USB power banks or camera USB ports.