personally i would go with maybe 1 finger. more of a performance fit and much more control over your boot ... and hence your ski. 2 fingers is huge. you'll be swimming.
btw, in ski boots a 27 and 27.5 shell are usually the same size shell; they just change the size of the liner. can't remember if that's how the scarpas are. did you try a 26.0/26.5 shell?