Hi all,
I've been lurking around these parts for quite some time and felt it's time to sign up!
I've been looking at home automation for quite some time, I've been living in rented accommodation since being at University so I have never been able to install any systems.
I'm getting close to buying my first house, so I've been researching different approaches to HA a bit more intensely.

The house we're hoping to buy does not currently have a burglar alarm, so this is where my search starts. Obviously, with us buying a house funds will be a bit tight, but a burglar alarm is fairly essential. If I can find a system that has a good security module, then it'd be a wiser spend of my money.

This is where your knowledge and experience can aid me. What system would you recommend? If you could start over again, what would you do differently? What's worked really well?

What I'm prepared to do:
I would prefer to leave existing electrical cables where they are. I'd prefer to have the HA augment the current electrical system. i.e. current 'traditional' light switches will still turn lights on and off. (I don't mind replacing wall switches and sockets though). I basically don't want to be undertaking an awful lot of electrical work. I can run data cables, and minor electrical work, wherever and I don't mind getting dirty, and in fact would prefer a cabled alarm system (something which seems hard to find as everything is wireless!)
I can setup a dedicated network for HA, and have spare PCs if there is a suitable software option. I also don't mind buying dedicated hardware.

I intend to start off small using the system mostly as an intruder alarm and a small amount of lighting control. I would be looking to expand the system further in the future though.

Wish list:
- Intruder alarm with text/phone/email alerts preferably with cabled sensors (not wireless PIRs) [PIR sensors used for intruder alarm, could work with HA system to know if room is occupied, etc) - Bonus ability of working with CCTV -
- Scheduled and 'Clever' programming. If it gets dark outside, slowly bring up lights inside if room is occupied.
- API or some ability to receive commands over network from another application (For example my XBMC setup could issue a command when a film starts, and HA could dim lights)

My current thoughts:
I quite like the look of Z-Wave. There's a fair few UK appliances available, and the z wave fibaro modules look ideal! I haven't seen much evidence of people using burglar alarms with zwave though.

It would appear I should avoid X10 at all costs.

I was unaware of IDRATEK before reading these forums, and it looks quite promising. But I would rather not lock my self in to one manufacturer, as I'd quite like to use this system for many years. Basically, don't want to keep all my eggs in one basket- unless it's a particularly strong basket!

Many thanks for your help!