Great Fishing features a fully built Fishing system complete with catching mini-game. The system is highly customizable to suit your game's needs from turning mini-games on and off, to difficulty settings. Fish and Bait is easy to add via data tables. This can be used out of the box to build a fishing game, or can be integrated into you current game to add another feature.
This system was built with Survival Game Kit V2 in mind, and is made to easily be integrated into it using the integration video. But it can be integrated into any project.
The fishing is replicated, but the inventory is not. I might revise the inventory in the future. If you integrate into SGK, it should be fully replicated, as you will use SGK's inventory.