Advice on project production

I am producing a presentation for a client. The presentation consists of a presenter on stage and a large screen of video content. The presenter needs to control the progression of the video content. For example, before the presentation starts the screen will show a loop of video, when the presenter wants to begin they activate the presentation and a second segment of video is triggered. It plays to the end and displays the end frame. The presenter talks and then activates the presentation again and so on.

I thought about authoring this to dvd but there are projector format issues and the client wants the presentation to run from a hard disc.

I have seen some discussion about adding a flash track to a quicktime movie, could this be an approach to the problem? Has anyone heard of this technique?

Can anyone suggest a strategy for producing the interactive element of this project in flash?

Thanks in advance!

Simon