Search: Sorting posts/pages via front-end

Hi,
I am trying to build something like a wiki but not quite. But a function i’d like to have i did not find as a plugin. Perhaps you stumbled upon something like this?

– I’d like to have all posts shown on the sidebar (frontend)
– Have the ability to drag one onto the other to make the dragged a sub-post (or sub-sub)
– These lists of posts should be collapsable
– Drag&drop to sort the posts/posts with sub-posts
– No worries about dates/taxonomies/whatever thats been built-in already

I am aware that this is not for what wordpress was built but it’s kind of short notice and the only platform i sort of know my way around.
So i am totally up for any advice on how to master this idea. Be it juggeling with pages and posts or anything.
The only must would be that this is done from the front-end. The result preferably looks and feels like a web-based software an not like a publishing platform. It should basically be a platform for a dissertation.
Also open to new ideas should i be totally off in my choice of platform because of this.

Skill-level of programming: Can google. Have no fear of trying. Can read and modify code.

Cheers