We are planning on going to Maui and Oahu for 9-10 days, and have an additional 5-6 days to go to either the Big Island or Kauai. We are a couple in our early 60s. We frequently walk miles on paved roads, but one of us has difficulty with hikes on uneven paths (e.g. high steps over rocks). Zip lines are out, as is strenuous kayaking. Also no activities (helicopters, boat rides etc) which can lead to motion sickness. We understand there isn’t any current active lava flows to view (that would make the decision, so please correct us if we are wrong). Which Island do you recommend and why? Thank you.