Can comment on a few of those; owned RX8's and AMC 76's, have skied B2's, Legend 8000's (if that's the one you mean), have a good friend who skis the Mission, another the Apache.
Given where you ski, I'd recommend the Mission, then the B2 and the Legend 8000 in that order. 76's are great on ice and in light pow, but not my choice for crud, chop, or float, and a bit much for a one week a year skier. RX8's are a bad one-ski choice for where you ski, period. B2's are easy easy easy, but that's their chief problem; too forgiving. If you are willing to drive them, they'll do anything you want.
Legend 8000's are a truly great all around ski, but opposite problem. I have a buddy who is also a high intermediate, also skis about a week a year, owns the 8000 in 172, doesn't much like it. Because he can't bend it correctly or do much beyond scarving, so he finds it an unstable handful. I like it a lot, but to me it's a soft short GS ski that needs decent speed and an edge angle to wake up and perform. So it'll ask something of you. Is that what you want? My friend owns an Apache, says it's smooth, versatile, and boring. Like the RX8, not for where you ski; too narrow.
OTOH, my other friend (and everyone else) raves about the Mission, especially as a forgiving, versatile soft snow ski, front or backside. Apparently not for ice. But of course, the Rockies or Wasatch never get icy.
So that'd be my first pick out of your list.
You've been on this quest for a while. Why don't you just take a deep breath and buy one of the above?