We're working on an improved installer either for the 4.3 release (late October or November) or the 5.0 release at the end of the year. We agree our installation/packaging system leaves much to be desired and is something we're hoping to have much better soon.
Putting them individually up on the download page is something we're considering (in addition to an improved installer), but we need to make a planned move to a new download component. Our current one doesn't handle sub-categories, and throwing every file for both Joomla releases on to the same long page would be a disaster as well
As for right now, the AUP plugin is actually in the main file you download in the first director you unzip with the main component. It's not in any of the other unzip's, so just look for it right in the main directory.
Hope that helps,
Alex