Design and create Layout/UI for Mac Application

I have all the specs for a mac application I am developing. I need someone creative to create JUST THE LAYOUT for my mac application (the .xib file). I will be making the graphics (logo, icons, theme, etc) myself and doing the back-end programming separately. I just need the layout to work off of. A .XIB file is an Interface Builder User Interface Resource file, and anyone who has experience developing applications for Mac or iPhone/iPad should know what it is. This project may require a .NIB file, instead of .XIB, but maybe you'll have a better idea of what type of layout my application requires. As far as mac applications go, it's a relatively simple application. I'll provide you with all the specifics of it (functionality, features, user abilities) and you can create the layout/User interface. I can show you mockups that I have so you get an idea of what is on the pages/frames, however, there really isn't a single layout element that I want to keep from these mockups (other than the user's abilities). I want to hire a layout designer that gets back to me quickly and that has a portfolio of Desktop Applications that you've designed layouts for. Thanks so much for your interest, Ben