Hi I am looking for a recommendation for a house alarm wired or wireless I have access to everywhere except the only entrance door but could add a pir at the top of the stairs pointing down to the door instead of a contact sensor, I fitted a CEF own branded wired alarm around 20 years ago but this was removed around 5 years ago when it started playing up, it is a first (top) floor flat with 1 door on side of building with a straight internal stairway up, so what would you recommend