Just for ones who are interested I provide a link to my OS X GUI design stencil I use for my own prototypes. It’s currently work in progress and still retain large portions of WireframeShapesAngles it’s based on (make sure to check the original, it’s pretty useful by itself). Future versions should have more controls, dialogs and other ready to use stuff, but if you’d liked to finish the work, feel free to do so.
So, here’s a link. Download and enjoy, it’s less than 100Kb anyway 😀