Buy a copy of "The Miepost" from Amazon and study it thoroughly if you have never been to Alaska. It will help you plan not only your route in Alaska, but all the optional approach routes to Alaska through Western Canada.
Also check out the Alaska TourSaver coupon book at their Website HERE.
. One 2/1 coupon for a glacier boat tour from Seward to Kenai Fjords NP will pay for the book.
The main highways in Alaska form a big loop, so the only real decision you need to make is whether to go to Fairbanks first or last! But two "must do's" for me are Valdez and Seward.
Finally, since your wife is apprehensive about the roads, have her look over the Alaska Marine Highway System ferry routes and schedule for either the trip up or back, at least from or to Prince Rupert, BC. Not cheap, but can be a great way to relax in a cabin on the trip home after putting many thousand miles on your RV. You may even stop at some ports that cruise ships never visit! Their Website is found HERE.
BTW, my absolute favorite town in Alaska is Sitka, the old Russian capital. And it can only be reached by ferry or air. My least favorite is Skagway--too many cruise ships and way too many tourists in a town with a winter population of only 600.