I'd like to second the request for a torrent. Adafruit, the torrent would greatly reduce your bandwidth usage (and therefore, presumably, your bandwidth costs), for at least two reasons: (1) at least some of the downloads would be coming from other peers, rather than from your site; and (2) the torrent protocol will verify that the file is transmitted correctly--people won't need to be downloading the file over and over again to get it correct.
I tried it twice yesterday--got 750 MB the first time before it canceled, and 866 MB the second time. The second one looked complete, but the sha256sum still wasn't right. I have no idea what you're paying for bandwidth, but that was 1.5 GB pretty much wasted. Even if nobody else were seeding the torrent (i.e., the download came entirely from you), getting the download right the first time is sure to save you significantly.
Alternatively, you could break it up into multiple .rar files with verification and recovery, or something similar. A direct download of a single ~900MB file, especially over HTTP (even FTP would be better) is just too fragile to be reliable.
I appreciate the work that went into building the distro; it looks great, and I'm looking forward to trying it on the Pi.