I was there last august. Home basing out or Anc is not a great idea. Everything they will want to do is 90 minutes or more away. The drive is pretty, but 3+ hours in the car every day is no vacation.
Stay a couple days in Seward, stay a couple days in Homer or somewhere else. I wouldn't spend more than a day in Anchorage.
Alaska is expensive. Like real expensive. Doing it on the cheap will not be easy. Try Turo for the car rental. VRBO for lodging. All the excursions will be expensive. Eating and drinking is high as well.
There are a million fishing charters for them to pick. I will say it again, flossing for salmon is mind numbingly boring and stupid. It is standing in a cold river foul hooking fish, hoping you hit one in the mouth. It works and you will fill the box, but not the kind of fishing I like. Go on a halibut trip. That isn't real sporty fishing either, but the sights from the boat are amazing.