You're probably not gonna find GC streams that easily on the web. In order to get GC music you can........
1) Rip the game iso yourself but the problem is that not many people can do that.
2) Find torrents of the game you're looking for and from then on after you downloaded the game, rip the streams off the iso with a gamecube explorer or something similar.
Some games use sequenced music so ripping off an iso is out of the question. Best thing you can do is make a gamerip if that's the problem.
Also, hcs64 is more likely choke because of bandwidth leechers. Just be careful with the server and keep the secret to yourself so hcs won't be forced to take the files down again.
Or he could make another site. (well pretty much a single page with links) Every one that dl's stuff from the main page could mirror (rapidshare, badongo, etc.) everything and then give hcs the link. (if that'd work)
If you are willing to mirror them all on your own webspace, that would be great!
Other than that, I believe that just about everything has been tried. The problem with rapidshare is dead links. It is a pain to have to re-upload every month or so. Torrents don't work because they are lack seeders and are generally slow. What we have here is very nice, but very fragile.
I don't have my own webspace, (I don't even have internet =X) but I'd gladly mirror them to other sites. (and I could seed once school starts again, It's not my bandwidth there, so I'll seed forever [until it gets turned off]; seeded a 7GB torrent to 425 GB uploaded in a week; might be helpful)