Work project, trying to figure out what steps to take

I took a new job for an agricultural company, but something unexpected came up that they want to develop. I'm trying to figure out if I need a Pi, and if so, the best steps to take to see the project to fruition. In agriculture, there's big silos that store grain. People have developed expensive systems to monitor that grain through large cables secured inside the bin. The cables are built of a string of sensors that measure temperature and moisture. The first picture is an example of the cable. Inside that green shroud, is a wire with these sensors on it every 4 feet. Each sensor has it's own serial number, and returns information regarding moisture and temperature. They are read through an app for diagnostic purposes - pictured in image 3, or are relayed every 66 minutes via cellular data to a cloud service that lets a customer read the data on the website or phone app. Those cables (sometimes a single cable, sometimes up to 6 or 8 daisy chained together depending on the size of the silo) connect to the board in the last image. That board has a two pin output that plugs into a device (image 5) you connect to via bluetooth on your phone that lets you see the information from the cables. The purpose of the system is to set a temperature and moisture range, and the system warns you if the grain falls outside those parameters. What my boss wants is a simpler system. One that runs off an Arduino or Raspberry Pi, that constantly monitors the temperature/moisture signals, but is connected to three LED lights to give a visual indication of the condition of the grain. Green means OK, Yellow means rising/danger, Red means check the grain. So basically the simple system would be Sensor cables > Raspberry Pi > Lights. Temperature and moisture range would be programmed via a bluetooth connection on a phone app. What I'm wondering, is where do I start with this? Arduino or Pi? Maybe online resources that would give me a crash course. Thanks for any input or help!