Since revisiting my retro gaming itch - I've also gotten into the soldering /mod and repair aspect of things a bit. I figure I'd like to learn how to keep these systems running in the long run, and rather not send them off for repair. I did a pretty ambitious project modding an Atari 2600 for RGB output. That was pretty ambitious for a first timer, but great learning opportunity. (actually did a test project before but paled in comparison)
I am actually looking into doing a Digital Audio mod on my gamecube too. I really want to get the best picture/sound for GBA games.
Check this out: http://gamesx.com/wiki/doku.php?id=av:nintendogcda
scary!!, if it requires modding a Gamecube Component cable....but I think that's just one option
As for repairing cables, depending on how damaged it is, it may be easier than you think. If you're interested, I could take a look if it doesn't work. If it works with simply taping it, you may be fine. If you want that 'pro' look tho, I'd have to investigate options. Just putting that out there
regards
p.s as much as I love my cats, one of them is 'bite happy' - especially on things I prize (leather backed chair corners / NES cartridges). If she went after this cord, there would be HELL 2PAY!