222404 Signup form with paid checkout

Hello! I'm looking to have a signup form for a competition that has a flat rate $20 credit card ([login to view URL]) fee. Each input field will be on its own page (ie: fill out name and hit submit and then fill in age on the next page etc.-this may change-)and will consist of: Name (first & last) Birthdate Sex: M/F Address etc... -these will change- The contest has 4 different age divisions. Each division has room for 30 people to enter. When the 30 spots are full, the contest registration needs to have a "This registration is full for X age division". The final page will be for CC information and will process the credit card with [login to view URL] with SSL. Please reply with links to current working Shopping Cart Solutions that you've developed! THANKS!