Oh yea Joe, absolutely more than enough for any and all maneuvers.
I am far more confortable with 120s than any other size.
I cannot really say, having no experience at high altitudes, but would suppose you made need more blow than here in the midwest 160s should be fine. If you get heavy with extra fuel, smoke, etc, say 65+ lbs, you will probably need an upgrade to heavier main springs and exhaust. The kit, as produced, is outfitted for +/- 55 lbs.