Thats cool you have a buddy out there with all the gear. Alot less worry, and certainly less expense. Wish I had that option!! If your hunting the higher elevations sure as you know drink plenty of water. I bring a couple cases of bottled water with me. I have a hard time trusting natural springs or streams. Must be a NY thing!! Plus saves filtering it. For mountain sickness, and if your high up you will experience it to some degree. At minimum you'll have daily headaches. So I suggest Alieve, and rolaids for the stomach. The outfitter gave us Alieve, as nothing I had motrin, advil, tylenol would touch it. The rolaids help the upset stomach from the change. Also don't pig out, eat small portions in case you experience some diarreha while there. Last but not least just in case you haven't been alreadly. Exercise, and start today. I'm sure your well aware of that too. Its important if you'll be doing alot of walking.
I'm hunting units 25 & 26. White River National Forest, Flat tops region.