Terri,
Your two options are indeed eDVD and Intellidisc. Eric posted a link to Alex A’s excellent tutorial on the basics of using eDVD 3 (it’s now at version 4), which is very helpful when you are first starting to use the application. eDVD 4 is the only way to do something as potentially complex as you describe. There is another article on the features available with the latest version:
https://forums.creativecow.net/cgi-bin/page_wrapper.cgi?forumid=55&page=https://www.creativecow.net/articles/manz_james/edvd4_rev/index.html
Intellidisc would allow you to have an ‘interactive’ map with changing text and video boxes. However, it will only work on a PC, and it takes some reasonable knowledge on html creation to put it all together.
One last thought, and this is coming from someone who has done a fair amount of these types of discs, I am not sure how much longer rom content enhanced discs are going to be supported for standard definition discs. The next generation HD discs each have their own means of adding enhanced content, which is departure from what is used on standard definition discs. I think future resources will be focused on HD discs, and alas, standard def discs are going to go by the wayside (as it relates to rom enhancement; I think video only distribution will be around for some time). eDVD 4 has dropped off the face of the earth so to speak on Sonic’s website (unless someone can point me to where they are hiding it now). Some types of content (like Flash) have in the past relied on Sonic to update eDVD so that it work appropriately–but if it’s not being actively supported, there will be limits to the types of content you can add. eDVD is based on Interactual Player, and it’s unclear as to what will happen in the future with Vista, new IAP players and the retro-workability of discs created with older players or based on older players and the new systems they will be played on.
I hope the discs will continue to play, but time will tell. For right now your first challenge will be to find a copy of eDVD 4. If you do, then there would be a way to emulate what you describe, but it would take some pre-planning and work to accomplish (but it would work well, and be fun for the viewer).
Jim