I actually made a spreadsheet about this today and went over it with an old statistics professor of mine.
I will post it in a couple hours when i get home and edit this post.
The excel function figures out the best allagan/myth piece combination assuming accuracy >= 472, and crit>det>skillspeed.
Of course the function may spit out a different combination based on your character's base accuracy w/o gear (depends on race and affiliation i think) and how much you value the other stats and accuracy cap you want.

I'll go into more detail when i post it up in a couple hours.