Z-wave alarm setup

Hi all,

I am looking into creating a Z-wave alarm setup for my home. I am located in Athens, Greece therefore I am talking about EU frequency peripherals here.

I already have an outdoor and indoor siren, as well as a minimote.

So far I have been using ST hub v2.0 along with a bunch of Zigbee HA 1.2 motion and door sensors but I am tired of cloud dependency. There are two options for me:

  1. Install a pro alarm solution from Caddx and forget about my existing DIY setup as far as security goes.
  2. Utilize my existing Z-wave items and buy some more (mainly door sensors) and setup a new system that is a based on a hub and/or software that run locally.

In both cases the alarm has to be able to connect to a professional alarm monitoring service, via landline/GSM.

What do you think? Is number two feasible? Is it worth it? Any ideas for cheap but reliable Z-wave door sensors?

Thank you very much in advance.