We plan on running ethernet/fiber (depending on the length of run and whatnot) to our shop/barn/etc from our house.

Ubiquity also has some awesome wireless options, but personally, I’d rather do wired.

In the field, we use cellular data (for RTK corrections and whatnot). It’s really the only option.

The deciding factor on what to use is really just the distance. How far away are these buildings?

Unless they support link aggregation and you know what you are doing (which you don’t, or you wouldn’t have asked), no. Don’t.