Would appreciate a link to your researched aerial and router. I'm sitting in the country with my phone in a metal kitchen bowl (DIY aerial) for maximum signal, and think I could benefit from some technology!
I have heard that the Huawei ones that accept external antennas are also decent, be it with a much smaller featureset.
[1] https://teltonika-networks.com/product/rutx11/ [2] https://poynting.tech/antenna-category/antennas/urban-rural-... [3] https://www.cellmapper.net/map
They make lots of different types: https://poynting.tech/antenna-category/antennas/