I'm searching for software for a site that will be similar to the Free iPod offers (Gratis Internet) except for a different set of advertisers.

Overall the same setup where a person signs up, completes 1 (or more) offers from my ad affiliates, they get a unique referral link to send to friends to get them to sign up for the program (or a seperate link to send to friends where they just sign up for special bonus offers from advertisers and not be a part of the program/get credit to earn free stuff). The system would keep track of the completion of offers and credit the users account with points/reward dollars and they can get free items shipped to them upon completion.

Is there a commercial package out there for this? I know their are many clone programs of the Free iPod, Free LCD TV, Free Xbox, etc. out there from many companies. If anyone has any recommendations, let me know. Thanks! :)