If you do feel a little cramped on the ER6 you can get footpeg lowering blocks and a bar riser. I run both on my Ninja and hated how the Versys felt when i tried it on a Kawi demo day.
Other bikes include a DRZ and KLR so i'm no stranger to the open ergos.
As far as long distance I think the one generally agreed upon need is a new/reworked seat. The bike will handle it fine.