Ultra Cart Integration

We need to integrate Ultra Cart with an existing website and with a new website we are building. You MUST have previous experience with Ultra Cart. We want to be able to collect shipping information first and then collect payment info on the next page in purchase sequence. Also, we will need help in setting up up sell pages. In order to program against this API you need to be very familiar with javascript programming. This is not for people that have never coded AJAX style javascript before. You also need to be familiar with Javascript Object Notation (JSON).