After years of searching, I have finally found a near-perfect solution to my needs: Stockbox Photo Software, made by a company in Canada (http://www.Stockboxphoto.com/). I was able to get this software up and running to service all my images in one day. It took only a few hours to customize it, and I am even able to put video clips on the database -- something no other leased software package has been capable of doing. Stockbox Software is both affordable and reasonably easy to install and administer, and it offers just about everything that I have ever wanted or needed for my website's image database.
It’s currently up and running at: www.norbertwu.com/lightbox/index.php
As far as I know, Stockbox is the only software platform that allows users to display any file formats that are viewable in a web browser, such as . gif, jpg, au, avi, aif, htm, html, mid, mp3, mpg, mov, png, ra, ram, rar, swf, wav, zip, wma, wmv and pdf. If the file format is not viewable from within a web browser, the system provides a link for users to download other formats and files so that the user can view or play them locally in the associated application.
Stockbox Photo is not perfect. The documentation is not great, and I encountered some obstacles that left me scratching my head until their technical support folks clarified things for me. Their staff seems small, which is reflected in their email response time. .
Movie files display in the gallery, but it is not possible to edit the movie files from within the system. The user has to choose the video frame that will serve as the preview frame of the video clip. Automating this process would be helpful. Because I do not have the time for all the steps that have to be taken to get video clips into the system, I have gone back to using Filemaker to show my video clips to clients.