Plc security & fire alarm

Hello everybody,
i am working on a security alarm system which is to alert a remote computer over the internet when intrusion or fire is detected. can anyone help me in any way ?choice of plc,HMIs, sensors and stuffs like that

My gut feeling with this one is that there is someone in the security field who specializes in this.

Just like robotics, CNC, vision systems, etc. can have applications controlled by PLCs, "canned" systems specific to an application tend to save money in the long run because someone already "did that".

I would "Google" the topic until I found a niche vendor.

I recommend a smaller size slc for this, like an AB Micrologix 1500. If all you are using is simple inputs and simple outputs, this should be ideal.