We are looking for something that at least appears to be in the wilderness, scenic, would love water, essential to have mountains in view.
Ok, here's the good part, there is almost no where in Alaska that you won't be in the middle of the above.
Since you only have a week, yes do the Kenai Peninsula. Valdez is beautiful and the Sea Otter RV park is right on the water with a view of the Prudhoe Oil Terminus on the other side of the bay. We watched an otter every morning playing in the water. An eagle was swooping about everyday.
They think of it as little Switzerland and if you are there when snow is still frosting the mountain tops it sure seems that way.
Seward is the best place to take a whale watching/glacier calving all day boat ride with the Kenai Fjords people. We took the dinner cruise and had a delicious salmon dinner near the base of a glacier which cracked, rumbled and crashed into the water. A black bear wandered near the waters edge on one side. We saw whales/puffins/sea lions etc. on the trip out. Very cold on that water, bring layers, hats and gloves so you can stay outside for the view.
Homer Spit was lots of fun to stay right out on, awesome food, especially the fried halibut chunks. In Kenai, we stayed at the Beluga Lookout rv park which is up on a scary bluff where the Cook Inlet meets the Kenai River. The beluga whales congregate there to eat the salmon when they start running. And there's an excellent Russian Orthodox church and a natural history museum within walking distance from the campground.
You will just be stunned by the beauty. Go, enjoy. Sorry you only have a week. You'll want to stay longer in every port.