There is a basic website (homepage and 5 subpages) with static content, we want to add something like a slideshow of current offers with custom images that would change every month. We also want to include an image gallery with effects like Lightbox.
The person who is going to add/modify/delete the images in the two new modules doesn't want to deal with FTP. According to your experience, should we install a CMS (Joomla/Drupal) for this or just create a our own basic image management system to upload/select/delete the images?