Which to mount my Garmin 840xs

[ranger1850]

I have a Garmin 73 DV on the left of the dash with Ram mount swing arm. I can put this same mount to my right, but I also saw a boat close to mine that has Ram short arm mounted on the gunnel. I included pictures of the two. Also I showed a picture of my dash area, the swing arm would go in the area of the yellow decal on lower right of the dash. I am just want to hear which ram mount to use. Thanks ahead of time.