Thank you for your replies. The last two posts kind of highlight my problem. The iPad does not have enough storage for movies and has other limitations due to not being a dedicated music/movie device. The longer post, while appreciated, just tells me what I already know. I know I need a storage device and a wireless network or cables, but how will the information reach my TV or stereos? I can go and buy an expensive Sonos, but if I've already got a wireless network and two stereos it is going to mean a lot of duplication.
What I need is a network-friendly box with a hard drive to store all the files and then some other gadget to get the files from my wireless network to the TV and stereos. I understand the principle of networks and streaming, but I don't know which products I need to achieve it. The £1000 budget was based on the Sonos bundle, but there must surely be a cheaper solution that makes better use of the expensive kit I already have.
Am I really the only person who has this problem?