Gary-
With my knowledge of physical fitness I've received from the Air Force as well as my job in the AF: Sports and Fitness, I must say that most of the above I agree with.
I'll give you my .02 about the elevation mask - DO NOT buy that. Eat right, run, and do a few sets of the 3 core workouts a day and you will suprise yourself how quickly you can get into shape. Pushups, Pullups, and sit ups. Yes, it's that simple. You may not look like Hulk, but if you wanted that, why you'd be on the bodybuilding form asking for advice. Stamina is what you are after for mountain hunting. Walk on a treamill that is inclined for a 1/2 hour tv hunting/fishing show. Load up a pack and do it every other time.
I can't stress enough how much of a waste the masks, supplements (GNC type BIG name "hulk powders") are. Get your nutrients from the food you eat.
Body weight exercises are the best thing you can do for yourself. There are plenty besides the 3 I mentioned, which should be a standard each and every day. Check out the 7 minute workouts, which are free in the app store. HIT - High Intensity Training is the second step in the process. Get that heart rate up and "HIT" it hard for a few minutes. Simple things; jumping jacks, lunges, high knees, burpees, etc. That will do 100% more for your stamina than bench pressing a plate 8-10 reps. I'd rather be able to push 30lbs for a quarter mile than 150lbs for 30 feet.
Best of luck to you in the quest to become physically prepared for the hunt. Keep us posted!