It's good that youngsters want to get involved in fund-raising like this but I can't see any of the 'big boys' in business being interested here.
The firms I would approach would be local small computer firms (or computer supllies firms). A couple of hundred CD-R's will only cost them, at trade prices, about �20 so it's hardly a big investment for them. Tell them that their name will appear as 'supporting Children in Need' on the disk labels and that you'll be asking the local newspaper to cover the story. (Most local newspapers love stories like this). �20 for a positive image in the community and free advertising thrown in? Sounds like a bargain to me!
Chris