[linux-audio-user] What wave-editor to use for voice removal?

Hi, For a musical I've to remove the background choirs from a karaoke cd. The CD sounds like it's MIDI, and it's some simple music. I hope I can remove the choirs by overwriting them with other parts of the song that have the same instrumental parts. The problem is that I can't find a good editor to do so. I need some multitrack capabilty, to lay all the different parts on different tracks for easy editing. I need some form of volume-envelope/automation for smooth fading of the tracks (fade in/out plugins are not an option because I need to tweak it and that's difficult with plugins that work on selections). The obvious candidates like audacity and ardour don't work, because audacity has no markers, so I can't find back the positions from where I cut and ardour is too buggy to use. I've looked at linuxsound.at for editors, but most are still too much under development. I hope someone here can give me a good hint on what editor can be used. Perhaps I missed a feature in one editor that can help me? What editor would you choose? Thanks in advance, Remco Poelstra