Modify phpbb forum open source script

I have a lot more plans for development but this will only be stage 1. It will enable me to start promoting the concept and I will continue with further development if I receive donations or if it gets used a lot. Stage1 modifications: - for submitted topics (suggestions) and also responses to the suggestions I would like a grey thumb up and thumb down hands, whereby the thumbup will turn green when clicked on, and the thumbdown turn red (I can create these icons for you). Each will represent a vote up or vote down. If the user votes up but then changes their mind, the green thumbup turns back to grey and the vote is shifted to a minus. - next to these two voting options will show the total vote count (how many people voted on it), and after that the net vote value (if 300 people voted up and 300 voted down, the net vote value would be zero) - and finally to be able to sort the suggestions/topics according to total vote count or net vote value.