I Want a High-end Router and Amplifiers that can cover All my Family’s Houses (40 Devices)

First of all, we live in the Countryside and WE DO NOT HAVE INTERNET CABLES, WE ONLY HAVE DATA SIMs.

We have 8 Houses in total, And here is their Layout:

https://m.imgur.com/gallery/OYacBzi.jbg

So we wanted to Unite our money and buy a Really Good Router and Amplifiers instead of having a Router in each house.

So What Router and Amplifiers do you Suggest i Buy? (The Router must have a slot for SIM)

And is it even Possible considering we don’t have DSL or Ethernet?

And can the Data SIM bear the 40 Devices connected to it?

EDIT: We Have full 4G coverage, and with my Huawei B315s Router the Speed vary between 5-25 mbps.