iPhone app - City Guide

We want to produce an application for the IPhone which provides a city guide. The idea in later phases of development is to add additional functionality to this application (including premium services that users pay extra for), expand the application to other mobile formats such as Blackberry, and create similar applications for other cities around the world. We want to build a relationship with a developer so that we can work together on other projects. We have a detailed technical spec and table containing diagrams of the way we envisage the pages for each function fitting together. There is a small amount of graphic design required. We would also need a back office system which would enable us to send content to users by new "push" technology in iPhone 3 and to update content on a regular basis. App must be suitable for submission to Apple - i.e. not buggy.