Modify PHPBB avatar similar to gaiaonline.com

Hi, i need you to modify PHPBB source code, so the avatar is similar to [login to view URL] forum. which user needs to buy for the avatar. and the source for them to buy is to post thread/reply and get gold for every post or by inviting friends. No need for the avatar items design, i just need a CMS that can add the avatar items manually. Please message me for further details and visit the site i mentioned for references. DON'T BID if you don't understand what i'm talking about