DCC is the default, basic, non-frills way of transferring to people on IRC channels. It's not supposed to be fancy or anything. It's just supposed to get a simple job done, simply, without taking up much resources.
If you want to explore more advanced ways of distributing large files to many people using many sources, use bittorrent.http://bitconjurer.org/BitTorrent/
If you'd like to find other advanced ways of distributing large files, look for alternative ways to download any type of Linux.. There's many people working on ways to make downloading Linux more efficient, and most of the ways they create to do the grueling task of distributing different versions of Linux can be applied to other very large files as well.
My suggestion is that you either have people download RARed files that are split into 14mb chunks which come with sfv signature files to verify the files, or you do things the new, cool, and exceedingly efficient way using bittorrent and md5 signature files.