I was in Park City two weeks ago, and my boots broke. The plastic just failed after 10 years. I went to Cole Sport and got a rookie bootfitter who sold me a pair of boots that were harder to ski than my 10-year old Tecnicas. I am $600 poorer and very unhappy.
See the website "realskiers.com" for some good information on bootfitting and boots in the shaped-ski era with specific recommendations for the Park City Area. I found the website too late so now have a virtually worthless pair of almost new boots.
If you can get to Solitude or Snowbird, it seems the person with the best reputation in the Wasatch is Steve Bagley, the owner of "Superior Ski". (Type it into google.) Jans in Park City is supposed to also be good, but they seem to have (IMHO) somewhat of an attitude. (I checked them out after my boots destructed.) Subsequently, I've been told to seek out someone named "squid", and go to the location on the Mountain, vs. the one on Park Avenue.
There should be fabulous snow when you get there,so good luck!