I have not personally found a major difference between fresh and frozen turkeys. One thing that is nice is that most grocery stores that I know of will order your fresh turkey in the size that you want so you can pick it up fresh a couple days before the holiday. One of those things you don't know unless you ask, that's one of the reasons for the bell at the meat counter.
People will always talk about what brand they bought the previous year, was it moist or dry, was it fresh or frozen. What I have found to make the biggest difference personally is to use a brine. This is about what I use but it sounds like you have one in mind already.
1 gallon and 1 qt. water
1 cup kosher salt
1/2 cup honey
6 cloves garlic, mashed
5 bay leaves
3 stems sage
3 stems rosemary
3 stems thyme
3 sprigs Italian parsley
Tablespoon whole peppercorns
Toss those ingredients in a pot, boil until the salt and honey are well dissolved. Allow mixture to cool(I usually do this a couple days before cooking the turkey) and pop the turkey into the brine mixture and allow it to soak adding/subtracting liquid to allow for your container/turkey size. Now I have heard some say to brine for an hour per pound, but I am always so busy putting things together I tend to not pay so much attention to how long I am brining it exactly. I would say probably around 12 -16 hours or so. I have had a turkey soak for as much as 24 hours with no issues. You will have a very moist turkey with a beautifully browned skin if you use a brine. After this, I pull the turkey out of the brine, remove the herbs and set aside and discard the liquid. Chop up the herbs, loosen the skin and insert the herbs beneath it and roast accordingly.