I use DraftSight [an excellent, free AutoCad alternative] for my CAD work.
After laying out property lines, building footprints and preliminary design work I generally import that into SketchUp and start modeling the fixed elements like buildings etc.
I do find that I begin to develop design ideas in SketchUp quite early, and then often import back and forth as the design progresses.
Generally my presentation output would comprise SketchUp images rendered in Twilight, a SketchUp extention and the CAD documentation which would often include 3D line elevations
imported from SketchUp
