Frankly I think you are headed backwards
I sell the cams and like that new 555 especially but you are at 9.3/1 headed for 9.6 and as soon as you hit the higher elevations that added overlap and duration will not be your friend.
Knowing what I know my recommendation would be the Andrews 32h or better yet Wood TW5-6. At elevation either will outperform the others mentioned based on the specifications and in the case of the two I recommend my personal experience. I have no experience with the 555 yet and steer clear of the 7, not that it is bad but I usually go from a 5 to an 8 based on what the customer wants. In that way there is no convergence, distinctly different results. If someone wants to pony up and go with premium valvetrain throughout then we correct the geometry, use Baisley roller rockers and recommend the TW408 or 400. The 555 has been an outstanding performer and seller (with stock 96 head castings) but there is no guarantee it will perform equally well in the 110, especially when the air thins out and the dynamic compression drops. Pipe will be critical as these heads have a lot of breathing potential and the pipe needs to actually scavenge or reversion will result, once again exaggerated at high elevation.