Between Arkon and RAM you should be able to come up with a solution that works best. The have a ton of different components, allowing for all kinds of combinations. I've used both for many phones/tablets over the years. Many of the pieces have gotten re-used in new setups.
But as to 'swing arm' you're going to have more challenges. As you put more weight out on an arm you run into problems with vibration and pendulum motions. It's one thing to have a desk or wall-mounted arm at home or in, say, a doctor's office. Those can easily be swung in/out of the way. But those won't work on a boat because you need to have a way to secure them, SOLIDLY, at both the stowed and in-use positions. This leads to a lot of 'fiddly bits' being tightened/loosened all the time. Which leads to wear on the parts, which makes them loosen over time, which causes the mount to vibrate, making the screen hard to read (and further wearing the plastic bits).
So it's one thing to have a mount, but swing arm? I've not yet found one up to the task.