Hi @Rexrider! I really recommend Zigbee with the Zigbee2mqtt integration; on the Sonoff side they have nice and affordable devices.
You have this motion sensor: https://www.domadoo.fr/fr/peripheriques/5261-sonoff-detecteur-de-mouvement-zigbee-30-snzb-03-6920075776119.html?domid=17
This door/window opening sensor: https://www.domadoo.fr/fr/peripheriques/5320-sonoff-capteur-d-ouverture-de-portefenetre-zigbee-30-snzb-04-6920075776126.html?domid=17
You’ll need a Zigbee dongle then: https://www.domadoo.fr/fr/interface-domotique/6315-sonoff-cle-usb-zigbee-30-antenne-externe-20dbm-v2-zbdongle-e.html?domid=17