I am not sure where you like i.e. housing estate, detached in country etc..., but additional to an alarm you should install a few lights around the perimeter of the house all switched by 1 PIR. It is a bold burgular that will stay at a door with a light shining directly on them.
As for the alarm, i don't think that you can disable your alarm with the autodialler but this should not be an issue as all newly installed alarms should stop automatically after 15 mins on the external sounder anyway.
Monitoring for us was about €200 per year in Dublin. Not Eircom Phonewatch but another Dublin based company. I used to set off the alarm intentionally a couple of times a year just to 'test' them and it always worked out ok.. Personally, I would not be a fan of Eircom Phonewatch, especially the wireless system they have.
If your house is not already pre-wired for an alarm and is not a bungalow, you will most likely have to go for a wireless option as to install a fully wired option in a 2 storey would be a pretty big and expensive deal.
PM me if you want a recommendation for a wireless system with an autodialler as I purchased one online last December as a present for my folks and installed it in 1 day on my own. Cost was around €500. (Not sure if I am allowed to recommend brands or specific links publically.)
In my opinion, an alarm isn't really of any use in a city without being monitored unless you are in the house when it goes off as everybody just ignores them anyway...
J