I never heard of du
working for zip files, probably you should use gunzip
for that purpose - http://www.abeel.be/content/determine-uncompressed-size-gzip-file
I think you should better ask on http://superuser.com
Command for listing .zip archive is:
gunzip -l file.zip
For other formats I'll quote nice example from here:
Task: List the contents of a tar file
Use the following command:
$ tar -tvf file.tar
Task: List the contents of a tar.gz file
Use the following command:
$ tar -ztvf file.tar.gz
Task: List the contents of a tar.bz2 file
Use the following command:
$ tar -jtvf file.tar.bz2