Monitoring my house alarm

I have a veritas R8 alarm system installed in my house with PIRs in different rooms. I want to be able to use the already fitted PIRs to monitor movement within my house without compromising on the alarm system.
I was wondering if anyone else has done anything similar?
Unfortunately my alarm system has no comms port for communication.

I do this using Z-Wave and a couple of the Fibaro Universal Sensors. These little devices allow you to parasitically monitor a binary sensor without effecting the original system. And they run off 12V. So you can install a couple of them inside your alarm panel and connect them up to monitor your PIRs and siren/strobe signals. In this way you get a read-only view of any motion detection and whether the alarm has been tripped or not.

I wrote a brief blog post about this…

They look really good but they are a little out of my price range.
I don’t have any Z-Wave devices yet and if I want to monitor all 8 zones and the strobe I’d be looking at £175 which means I might as well but a new control panel.
Anyone know of anything else that would work with an arduino type device? I’m right next to Ethernet and WiFi so connectivity isn’t an issue.