For CAD you might look into Sketch-up. Very easy to use (created for designers, not engineers). I think it was created for the apple (Machintosh). http://www.sketchup.com/ Before buying it, you'd want to make sure it will export as a file that your CAM will be able to open.
I'd also look into Rhino 3D as a CAD program. They recently added a CAM pluggin for it which should streamline the whole process considerably. I'd be surprised if it wasn't available for Mac.
I don't know of any stand-alone CAM programs for Mac.