Sinope Calypso Hot Water Heater Integration

What is the easiest way to integrate the Calypso HW heater controller into HA?

What model?
Do you have any remote temperature sensing as well, either at the unit, or elsewhere in the house?

We have not purchased it yet. I was going to get the Zigbee version. I have several temp sensors, but this is for the electric hot water heater.