It may be large, but it's the best chance of getting a workable solution. I suppose you could host the modules on your website in the various forms needed then have your install script hit your website, that way you still have complete control but the download is slightly smaller for some people. But of course that solution still breaks some of the time and is pretty stupid.

People want a solution that Just Works. I seriously doubt people will care about the extra 10 minutes of downloading required to get these modules. If you really cared about those few who would care, simply post two versions "version 1 with all modules needed" "version 2 with install script" or something.