Changing my thermostats

Hello guys I want to change my neptronic thermostat so I would be able to control it via a third party system. Any thermostat with IR/Wi-Fi/Serial interface is acceptable. I have sent to NEST they believe it is not compatible I don't have any experience with HVAC and thermostats The TRO5404 thermostat is as per the link: http://www.neptronic.com/pdf/Controls%20TRO5404.pdf