You're not going to be able to (reliably) see grizzlies catching fish in any of those locations. We did a hike called Russian Creek that's supposed to have decent odds, but no luck, though we did see the salmon jumping, which was cool, and we saw a grizzly on the road nearby. To see the bears, you'll need to fly to Lake Clark or Katmai NP (though flights leave from the areas you mentioned). Ask
@Something Fishy for more details and recommendations.