affiliates, referrals application development

I am interested in developing an intuitive, easy to use affiliates, referrals application. Also I want to have the ability to see ROI statistics. there will be more affiliates type: Pay-Per-Lead, Pay-Per-Click, Pay-Per-Sale. I do not have the knowledge to write you clear specifications - but I understand well the Internet technologies, I use to program in php, mysql and stuff like that, so logical am ready to "speak" with you. the contract will be 1. for the application development, testing, customizing (I will use this on an casino, poker games web site) 2. monthly fee for maintenance and more customizing. what I need fist from you (I will appreciate your attention) - a small list of Technical Specifications with time and costs. you have the freedom to choose whatever you think is the best (already build applications are accepted. ex: the integration of urchin -[login to view URL] - for the ROI calculation)