Sports Prediction Game

I am looking for a php developer to build a sports prediction site. The game is simple. We (as the site administrators) pick a roster of events, the players must select the winner of each event (not individual matches, the entire event - i.e. Champions League, Wimbledon, US Maters, etc.). If you don't make a prediction you get minus points, if your prediction comes last you get minus points. There are a few points permutations. The site must allow players to login and make predictions within a certain time frame (i.e. up until 15 minutes before the event begins.) There must be a log of the players with their scores. The site needs to send reminders for predictions and results. There is more functionality but that can be discussed later. We have a large pool of people who currently play this game. Currently we use email and MS Excel. I have created a flow diagram ([login to view URL]) to give you an idea of what we need. I have lots of experience with CSS and will be able to style the site.