The mechanics of those two machines are very different and would be a bigger factor than seated or standing. I have had good luck with a combination of dumbbell laterals (including one arm at a time) , cables, seated overhead barbell presses and standing push presses. The standing version could create elbow stress but that is not because it is standing but rather because of where you make contact with it. If you have access to a Freemotion (or similar) cable set-up that is a good option, but there is no single best one in my experience.