Help in choosing a geothermal thermostat

[spagettilegs]

I have a “Theben RAM 797” heating thermostat Which controls a geothermal heating system which needs to be replaced. It’s been there for about 20 years and I would like to use something a bit more modern which I can control remotely.
I have had a look online at various thermostats I’m a bit confused as to which one I need as there appears to be different types some of which may not be suitable for my needs.
I wonder would somebody be able to give me some advice as to what thermostat I specifically need. for my particular system.
Thanks in advance

 

[ShaunCorbs]

You can use any eg nest

 

[spagettilegs]

You can use any eg nest

Thanks. Am I restricted to only using a nest thermostat, or are there other types of thermostat I can use? Thanks

 

[ShaunCorbs]

You can use any will require a bit of a rewire but any is fine which one are you looking at ?