For hiking the stair climber is going to be your best/worst friend. I highly recommend the sit down bike for cardio. You are bending your knees to get them use to moving with no impact while you're keeping your heart rate at a steady pace for a sustained period of time. 20 minutes minimum. I watched a guy do just this at the rehab VA rehab facility over the past 4 years don't know him personally but this dude had jowels no neck. He now rides a bike 30 miles every morning weather permitting and on hikes that we do he went from almost dieing (I seriously thought he was going to die one time at the start) to staying in the front pack on 6-8 miles what i consider strenuous hikes.
You can do it. Most likely see you out there at some point. March 9th start