Help with first minimal set-up

Yes, I was in a meet up they gave last week. But they use a Multitech as getaway; and we are trying to start a little lower.

I have researched what you have told me, and I think that I will go with the RN2903, which I will link to a PIC18LF25K50, as it is mentioned in the rf datasheet.
And for the getaway I give a first try with the single channel raspbPI but with the Hoperf RFM95W. In one post it says that it should work in the 915MHz freq with some minor changes, what do you think?