Rating system with like counts

Hey!

I would like to insert the following rating system on my page:

Every comment on a post can be liked or disliked with a small box next to each comment.
The likes are going to be added up per user and i want to have a page with a ranking of the users with the most likes on their comments.

Does anybody know if something like this exists (didn’t find so far), or if not could you give me an advice which plugin should be easy to modify to get what i want?

Would be awesome!
Cheers,
Ole