the 7zip doesn't seem to work as it supposed to to change the tar.gz to zip. If the files have to be uploaded in zip, why can't the download be offered as such?
Topic on Talk:Download/pt
Fies don't "have" to be uploaded in zip. That depends on the method you're using to upload files. Hostings that don't provide shell access may let upload zip files and allow to decompress them from the web interface. However, they may also support .tar.gz files. tar.gz is the most common compression format in *NIX platforms.