My favorite fitter in the area is Brian Britton at Extreme Snowboard and Ski, it's more or less across the road from Alpine.
Donovan Carroll is also excellent, as noted above. The main difference between the two, I think, is that Donovan is a Superfeet person and Brian is an Instaprint person. Instaprints work better for my foot, so I go to Brian.
I think either of these guys is honest enough to know if their given footbed isn't going to work with your foot, and direct you accordingly. Both are the managers of their respective stores, and both get a bunch of area instructor business. Beware of anyone else in either store, though. There are a couple of guys at Extreme that are good, but it's kind of luck of the draw. I am not familiar with any staff at Alpine other than Donovan.
For reference, Extreme sells Atomic and Lange boots, while Alpine sells mostly Salomon and Rossi boots. If you're modifying your existing shells, it might make sense to go to the store that sells that shell as they will be more familiar with the little wierd things about each one.
You really can't go wrong with either, but make sure you call and book an appointment first as they are busy. If you go to Extreme, tell them Phillip Sink at French-Swiss sent you.