iphone art sales application design

I need someone who is able to design an iPhone application that will allow users to browse artists work. From this the users are able to make a selection of the art piece and purchase it. In sense it will be an iPhone application art gallery. Within the app people will have the ability to sign up and then add their own pieces of art. As photos. Which will fall under the recognized categories. The app needs to be clear and easy to manage but yet still have deep range. Being able to narrow the search is also important. So that customers can get what they want fast. Also would there be a possibility for the application to be connected up to. Website where they would work together and in sync. Your help with this will greatly be appreciated