You can download a copy of vBulletin through the special options without images included. This is because uploading images can be a pain in the butt (since they're so big). However, in your case, it would be the best choice.
At
http://members.vbulletin.com - Select "Download vBulletin". Then choose "More Download Options" from the radio button at the top listing the version number. Under "
Download File:", you should select "
Package - No Images".