I have an iPhone developer creating an application but I need to have a nice interface created by a designer.

There are four main screens that I would need to have created from my rough mockups.

I would like to do this in two steps. First, have three or four versions of one screen created that would show three or four different interface styles. Then, once the initial style is chosen, have all four screens created in that style.

If you have done interfaces of similar apps before, please show me examples.