I went into the shop to take the boots back and, after close to 2 hours in the store, walked out with the very same pair of boots. I was basically told that no boot with adult soles will fit my size foot and that I am basically "screwed." Their words, not mine. I tried on the Tecnica Attiva race boot with a 260 mm sole, but it still felt too big and was much roomier on the sides and the top of my foot. I was told that the junior version of the Diablo would fit the same way and that it doesn't come any smaller than the 260 mm sole.
So, according to the store, my options are:
1. Return my ski/binding package and start completely over, buying the junior version of everything.
2. Purchase a custom line to take up some of the space.
My salesperson/bootfitter was convinced that these were my only two options. When I mentioned some things I've heard here, he got so exasperated with me that he left to get some footbeds and just never came back. I left the store in tears.
If Sierra Jim, Epic and Mt Lion say that you can get an alternate boot that will fit you and fit your adult bindings then that is the truth.
The EpicSki Boot fitters are good!