Definitely the first one. Putting parts together is a delicate process, you wonʼt have the equipment with you all the time (maybe except the fishing line, and obviously the hooks).
After chatting with someone else about it I'm now thinking of separating the hooks from the process to be more like the bait - you can have a bait box, and also a handful of hooks that you take with you that attach to the completed rod. So while you have to craft the rod at the house, you can attach hooks and bait 'in the field'. :)