If you would use QUOTES and syntax in your text, it would be much more better to understand. It would be even more better if you
provide screenshots.
Ok, as far as I understand, you need kind of
Voting, right? People put +1 or -1 to the certain topic. Or per the certain message?
Anyway... you may check the
related thread... it has been already discussed, and I owe the add-on which allows to collect votings for a topic. It's a paid add-on. I don't have anything related to the voting per message.
As far as I understand, you want it for free, so I don't have actually to suggest at the moment.
Also, this function is not related to the
system reputation in any way. It's the same public opinion as anything else. And public opinion is never related to kind of reputation. It's very subjective.
All in all, "reputation" itself is a very subjective term ;-)