Depending on the budget and sparky I would just let them install everything and then change it later. Make sure you tell the sparky you want a nutural at every light switch.
If you got money to burn C-Bus - Bindings | openHAB
https://www.clipsal.com/products/c-bus-control-and-management-system
If you want to do it yourself and pay less then 8266 are the way to go.
I use some tasmota stuff to make implantation a 5 min job.
If you want the kettle boiled when you get there
For my fans and lights I use SONOFF IFan03+RM433 flashed with tasmota like $15 each with remote. I just bought a blank wall plate from bunnings and double sided taped the remote to it.
So I automate 4 rooms with fan OFF/SLOW/MED/FAST and light ON/OFF with google assistant for under $100 thanks to openHAB community