I am planning to build a website for a photographer and am in search of a photo gallery script.

I am looking for a script that can:
- protect photographs with water mark
- offer images for payment (shop)
- be styled in any way
- works in combination with phpwcms
- login for customers (option)

I have seen some examples of scripts being used:
- http://www.weitzelmedia.de/ uses photokorn in combination with phpwcms.
- http://www.amberimages.net/ uses a CGI script (ImageFolio?) in combination with phpwcms.

I am fond of the websites just mentioned (weitzelmedia/amberimages) and it seems these scripts work well. Photokorn is only a paid script and Imagefolio is CGI, while I prefer an open source php script.
Can anyone recommend an open source PHP web-based multimedia gallery script?