The majority of people, especially beginners, are often better off with a rigid kayak. Inflatables do have their usages, however stiff hulls are simply a lot more flexible - especially if you intend on going out on the open ocean. An inflatable kayak would not be my front runner if a curious shark decided to take a test bite out of my kayak!
With that in mind, feel that about where you will certainly be fishing. If you intend on visiting the ocean, which needs primarily straight-line taking a trip over ranges with few turns, a long and also narrow kayak is more suitable. If you intend on fishing in a smaller lake or creek, a shorter, wider kayak is the method to go.