I need a programmer for Raspberry Pi or Arduino

I would like to set up a humidistat controller using an Arduino or Raspberry Pi system. We are trying to control relative humidity in a system for two different experiments. In the first we are aiming for a range of 92-95% RH during the night and 68-72% RH during the day for 12 days; in the second experiment we are aiming for a range of 92%-95% RH for 3 days and then dropping to 68-72% for 9 days. To do this we would need a minimum of 2 humidity sensor inputs across the space (preferably 4 sensors across the space), have these readings averaged, and have the system controlling a 120vac relay that feeds the humidity system.