I have DeFever 44. It came with 25 x 20 props if that means anything to you. With a full load of fuel and water the boat reaches 2,350 RPM with a clean bottom. It may be slightly over-propped as the FL120s should ideally reach 2,500 RPM. It does not concern me or would it for many others here on this forum.
I am curious, however, why you would determine to replace your props without knowing what the diameter and pitch you have. As for spending new money to have spares on board, that would not be something I would do. There are so many other ways to spend boat bucks. Your DeFever has a full-length keep giving good protection of your props. Having spares, although for some would be peace of mind, on your boat would be a very expensive just-in-case. Others here may have a different opinion.