no matter what you do to that P2, its not going to be a good climber as a well designed light XC bike....the geometry is not going to change....specially not for climbing....out of your pics..I like the Rockhopper and the Trek 4500.......but, in my opinion, the Trek 4500 would serve your purpose better. Rockhopper uses pretty large size tubing and they are not very quick for XC......