Thanks everyone for your replies!

I'm afraid I now have more questions though

Noel - I have read the wiring guide (and would recommend it to anyone else in my position - very helpful indeed). I'm certainly considering star wiring now. I've already ordered a lot of Cat5 and Cat6 in various colours for various things, and I already have patchbays and things from work so nearly ready with that side of things.

I'm still not sure what to opt for by way of audio stuff - both cable itself and the system which runs it - it needs to be a relatively affordable thing at this stage but without ruling out the possibility to upgrade in the future. Any thoughts? In fact I'm still open to suggestions on general media and distribution - I have a Topfield freeview recorder, DVD etc, and I'm hoping to hide these in Node 0. Maybe XBMC is an option?

Paul - It's interesting what you say about C-BUS, I hadn't thought about it as a gradual upgrade path, but it makes sense. Also, the pink Cat5 is good - I have been wondering about how to use cat5 in the backboxes while staying inline with the regs. Any idea where I should buy it though? Although I've only googled it quickly so far I haven't found it in the UK.

For general control I'm considering getting HomeVision (especially as there's a discount on offer atm) - but my only concern is that I might be buying into old technology? Now I don't want to start an arguement here - just interested in people's opinions

I realise that it's very reliable, but is it the same unit that it was when it came out or has it evolved? The pictures on the website of the TV menu look very dated indeed... Let me know what you all think. Is there anything I can't do with HomeVision that I might want to? Also, how useful is the two-way IR? Do people keep the unit in their lounge? If not, what's the IR actually for?

The last question really is do I need an alarm panel as well as HomeVision (or similar)? What advantages are there? I'm sorry if this is a stupid question - it's not obvious to me at this point

Thanks a lot for all your help thus far - it's really helping me make up my mind!