My contractor replaced my 10-years old system with Carrier air handler FV4CNF and compressor 24APA736. But they kept the old thermostat (a very basic one). I read that I should use a thermostat with dehumidity function. I asked them about Edge or Infinity controls, but they are not familiar with those. Which is the best thermostat to go with these two systems? Does the contractor need to install an extra wire from thermostat to control board in order to use the two-stage feature?