Thanks for reaching out to us. Hello from Colorado!
We certainly appreciate your interest in our product. As you mentioned the voltage is different as we supply a power adapter that is built for US standards, so you would need to source your own adapter to fit your electrical requirements. In regards to the connectivity, cloud, timezone, etc... you would not have any issues with this.
The Iro can only control 24VAC solenoid valves so if you were planning on installing this yourself you would need to be sure that you are using AC valves and not DC. We don't really recommend any specific brand. I would just do some research and see what you are most comfortable with based on review and cost.
One thing of note though. The Iro is not certified outside the US, so you would not be able to purchase one from our website. If you did end up purchasing a unit Amazon will be your best bet, but note that the unit will not be under warranty.
I am not sure in regards to the rainwater catching tank. I would assume this would feed into the irrigation piping, but would need to have a mechanism to trigger it open, kind of like a master valve. The Iro would be able to trigger this open but it would need to be wired up. What are you thinking you will do for this? I am curious.
Thanks again Boris.