Personally, I find mod installers somewhat annoying when the game has a well-defined structure. Hopefully a nice rar version (sans MMP) will be available as well.
What if the installer checked for the presence of the proper MMP version, then downloaded the pack(s) if they were missing? That could potentially waste less bandwidth..
Each pack of the MMP comes with a "_credits.txt" file, though it doesn't list any sort of version numbering... It would probably help your installer if it had such things in it.
