Speaking from the perspective of a speckled trout/redfish fisherman, the knife I would like would be a Swiss Army Knife Tinkerer. Two blades, tweezers, toothpick, Scissors, bottle opener/screwdriver, can opener/phillips screw driver. most useful knife I own. Regarding filet knives there is only one choice: Dexter Russel. You want a 7" thin flex blade fillet knife. Inexpensice and the last you will ever own. The pair should not cost over $50.
As far as bird knives-Phooey! I use a pair of game shears on my birds.
Gut hooks? use them to scratch something ot straighten them out and use them to pick your nose.
One thing about the Swiss Army Knife-try not to let anyone else use your toothpick.

You might want to get him one of these-I have one and it is wicked cool. Have never caught anything big enough to use it on, but sometimes these things just call out to you "Buy me"
4in. Hook, Center Pull, 1/4" diam - Barr Brother Hooks - Processing - Shop