Leaderboard

You shouldn't break neutrals for anything! I imagine using a relay from a programmed output to trigger the emergency stop input? Why not a lockable isolator?

So I take it you are using anti mask and the fault output on these detectors?

They are good - but will be potentially blinded by the light / triggered by heat gains from those big windows. You definitely want to consider a corner mounted, pointed away from window, dualtech i.e. MW/PIR DT IMHO TBH I only ever use ceiling detectors in wide open office spaces and as a last resort - if I had as good access as you seem to (I wasn't sure if you did being it was a flat) I'd go corners every time. I was going to suggest a ceiling one, maybe, in that living space narrow bit, but I really wouldn't bother, tbh

Nope, most manufactuers don't do door contacts - buy Knights or Elmdene, avoid DIY 'range filler' stuff like Honeywell contacts. I would wire using EOL / FSL so be sure to buy contacts with built in resistors, you will want 2k2 for tamper and 4k7 for alarm. The colour code for Elmdene is 'Red' for those, a lot of the Knights products are more universal. GSM is yesterdays tech, so whilst proper monitoring is always recommended (someone external noting that the actual alarm itself is always talking back, i.e polling) the ComWifi module is very popular - BUT - if this is a 'new build' and you can get wires to the box, I'd go with ComIP and wire it to the router. Saves a lot of greif.