I haven't been able to pull up any information on the props or the motors.  I need to be able to fly at 9 to 12 thousand feet above sea level.  On an Iris+ this requires some small modification (longer props).  

There are online calculators to figure this sort of thing out.  Once we get information on the props and the motors (and overall weight with GoPro installed), what site do people recommend?  Is it difficult to use these online calculators?