Developer (Perl/JS) needed for web-based help system

We require a basic web-based 'help' system that contains and lets us edit the manual / help text for our online client platform. This is a stand-alone system. From the user perspective, it has the usual index / search / navigation system. It links to our platform using URLs, i.e. a click on a help icon from our platform calls a predefined URL which brings up the help system (in a new browser tab) and opens it at the right section / anchor.

Environment requirements:

- Linux server
- Perl for server-side, Javascript for browser-side

Functionality requirements:

- WYSIWYG editing of content, focused on key formatting features
- Ability to add pictures, and set scaling
- Global styles for headings, lists, text, etc
- User-defined levels of chapters/sections
- Access control using information in the platform cookie

From an editing vs viewing perspective, this will be very wiki-like in approach, i.e. no separation between 'front' and 'back'.

Note that we are not interested in a modified version of a pre-existing package that has a much larger scope. We want this to be lean and mean, focused on the requirements, and easy to maintain and extend. Feel free to suggest implementation of an existing package but it must meet all these requirements!

Please indicate your expertise and experience in this specific area, without this we will not consider your application. We're looking for an expert and not a jack-of-all-trades.

This project will be structured as a fixed-fee element for the basic framework, and hourly fees for the enhancements. Your proposal should indicate both; the details we will work out together.