A fiberglass reproduction is by far the easiest route. For this you only need to take a few color photos of the fish from the side and measure its length and girth. Then you can release it if you like. For a traditional skin mount, also take photos before the fish's color fades, then freeze the fish, making sure not to damage its fins or tail. In all cases, the appearance of your trophy ultimately depends on the artistic painting ability of your taxidermist. Note that you can also buy a reproduction trophy that you didn't actually catch and spend the rest of your life lying about it.