Spec me a home server?

[Audigex]

Hey guys and girls.

I need a hand speccing up a home server as cheaply as possible.
It will be running:

• some linux distro or other (yet to be decided)
• an apache (+php/mysql) server used mainly for testing and small scale demos
• general file storage and serving up of media to the other machines in the house
• likely a home CCTV system of perhaps 6 cameras.
• a printer

If the number of machines it's serving makes a difference, I'd assume it to be 3 laptops, 1 desktop and 1 HTPC. With likely no more than 5 concurrent users on the apache server. It's also unlikely that more than 3 machines will connect to the media server at the same time.

What I need:

• A case with sufficient cooling and room for 4 HDDs
• A small hard drive for the linux install (80gb would likely do)
• A bigger hdd for actual file storage. Perhaps 320GB for starters, adding more later
• A PSU with enough juice to run the thing
• A motherboard with the ability to attach 4 HDDs and onboard graphics
• CPU & RAM sufficient to run the above (although I can cut the requirements if the budget is a problem)
• DVD drive (generic)

No screen/OS/keyboard/mouse/speakers/webcam etc required.
Budget is "as low as physically possible", £300 or less would be great and hopefully achievable. £400 is absolute top end, but I'd really prefer less.