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Instead of using iTunes Match, you can use an application like Senuti to transfer your non-purchased songs from your iPod to iTunes. See > http://www.fadingred.com/senuti/
In that case, you can use iTunes Match to upload all your songs to iCloud. In that case, your music won't take any storage on your Mac and your iPod, and you will save storage. To purchase iTunes Match > http://support.apple.com/kb/HT4914
I told you to use Senuti to save the money that iTunes Match costs, but as you want to save storage, you can use iTunes Match. Note that you will have to connect your Mac and iPod to the Internet when you want to listen to music
You cannot upload music from your iPod touch to the cloud using match. Your music needs to be in your iTunes library on your computer. Match scans your library and matches or uploaded you music as appropriate. Once match process is complete you can turn on match on your iPod. I have read that this may delete all music on your iPod but I have no experience of this.