Yes I can help you with that 
I've had a Photon + RFM95w Radio up and running for almost a month now and it's proven to be a reliable wireless platform.
Using Adafruits RFM95w Breakout this is what it looks like when connected to a Photon
And for a Sensor Node, you will need another MCU + RFM95W radio to send data back to the Photon. Adafruit carries these also but there is a company that makes a nice unit that is setup for solar charging + has built in Flash storage and it's made by a company called Rocket Scream
You're going to need the RadioHead library to get both units communicating together. To figure out how to set that up in Particle DEV follow this thread and read it from top to bottom before starting and you should have no problems getting both units going using the Reliable Datagram example code I posted towards the bottom.
Let me know how it goes