D9 has designed the "cleanest" means of mounting a GPS in my opinion. All that is needed is a single RAM Mount arm because he has incorporated the RAM ball into a replacement stem nut.
Here's a picture of an early prototype on my bike.
...and here's one of a Veypor mounted which is similar in size to the Garmin Zumo you're looking at.
...and another view.
(Go to my photo album (below) for larger, more detailed images.)
