Programming a Dreamweaver extension

Question

Hi. I'm writing a Dreamweaver CS4/CS5 extension to allow users to insert HTML5 video tags but with a dialog box that allows them to customize it. It also inserts a JavaScript library in the head of the page along with a CSS stylesheet link. Here's what the user needs to be able to do:

1. See a dialog box that allows the setting of any number of SOURCE tags. Each source tag can be of a number of types (MOV, MP4, OGG, WEBM). As a SOURCE tag is added, the dialog has option to add another blank one so the user can fill it out.
2. For each SOURCE tag, the user can "Browse" and attach a video file of those formats.
3. User can "Browse" for an optional POSTER image.
4. User can set the width, height, LOOP property, CONTROLS property, AUTOPLAY, PRELOAD ("none", "metadata", "auto").
5. Or the user can set the video tag's SRC property directly without setting any SOURCE tags.
6. The user can insert any number of these video tags and then be able to select them and edit them via the dialog box later.

Is this a Behavior or Insert type extension? Can you point me to a tutorial on creating an extension similar to this? Thank you.