I would look into Linux Live Scripts from http://www.linux-live.org/
These scripts allow you to take any distribution you want, run a few scripts, and you will have a live-cd. If you start with something like Gentoo, then you will have complete control over what packages you want on your CD. If you want something that is less effort then that, you can start with slax, a distribution that was made using the scripts (so you can decompress, edit, and re compress it)
These scripts will make a compressed filesystem (using unionfs), but the scripts allow you to compress/extract files without very much effort.
If you really need a live-cd that has no compression, you may have to make your own (as I have not seen any). Try: http://gentoo-wiki.com/HOWTO_build_a...D_from_scratch