Maybe having a Manning list would be helpful here?
If so, I have an idea. What about using Google Drive Spreadsheet ("Google Excel")?
You can create it in your own (virtual) Drive, post a link in your event-announcement and set the sharing rules the way you want (link-visitor as a viewer, a commentor or an editor).
It might take a bit of time to create (I can send you a template, let me know), but it should be a lot easier to maintain than having a Manning list here in a forum.
Anyways, I'm really looking forward to this event. It sounds very interesting (and difficult)!