Best thermostat for a heater-style home

Hello, I’m looking for a good thermostat for a home heated with a gas water heater and multiple heaters around the house.
The heaters are not controlled individually, my current thermostat is a Bticino Smarther, which basically is just an overpriced relay.
Lots of people suggested Honeywell products, I was thinking about getting myself a T6 Pro, but I have no idea if that would work for my setup. On the product page, the pictures mention a fan (which I don’t have), and it uses lots of cables, while I only have two (the contact that gets closed when the gas heater has to be turned on).

What do you suggest?