[solardev]

I think that works well for popular torrents (Wikileaks, etc.) but not so well for things that only a few people would download. The seedbox ends up being the primary host anyway, which is kinda what the OP planned already (i.e., a torrent yes, but in conjunction with offsite backup + http hosting).

Bittorrent isn't a guarantee of reliability, it's just a way to distribute files among multiple seeders. But that assumes there will be many seeders, which for something like this probably isn't the case.