Hi Paul,
My PHP is certainly limited, but of C, Python, Processing etc I'm thinking its the quickest for me to continue with. For now my server is running win7, but I have a few machines I have lying around I can turn in linux boxes. As for relays, they will be controlling light rails, appliances and Solenoids.
The {} was just an example to break it up so its easier to read here. I knew I should have clarified that one when writing!!
The idea of the sensors attached to the controller is so the database has info on every room, I can then work on getting the server to trigger the relays depending on certain actions, ie dont turn off the lights when PIR detects movement. Turn on fan if over 30c etc etc.
Hope this helps to clarify. I currently have an arduino flicking of several relays around my house, but its a messy setup and I currently trigger my lights with 192.168.1.1/?2=on etc 