Finish building a Backbone.js/PHP/MongoDB web application

This is a web application that allows users to book cruise excursions. A solid knowledge of Backbone.js is necessary. The backend is a PHP/MongoDB internal API. The application is already started, but I need someone to take it over and finish it. What's built so far: User signup, user login, user profile editing, cruise database integration (a DB with a list of all cruises and their schedules across the world), cruise/user association, excursion DB started.