Best Mobile Hotspot, Router, Antenna for RVing?

Question: We travel a lot in our RV and need reliable, secure and relatively fast internet service while at campgrounds and remote locations. We don't mind spending a bit to get something that we can rely on. KnightHawk comes highly recommended - but which device or model? We have Sprint/T-Mobile as our Cell carrier if that matters and our RV has a built-in Winegard wifi extender, if that matters. Streaming is not something we do a ton but may do more in the future. Primarily we need internet access to conduct business on secure websites, pay bills, email, etc. Recommendations? Thanks, NovicePhil