enlarging/heightening the superstructure would help, or lowering the relative large beam (by increasing length and/or draft) or enlarging the radar suite.
without full calculations I cannot really say how it would end up, but just keep in mind the center of gravity should be higher then on the perry, and the higher you add weight, the better it is. you have to reason a bit, if you enlarge the beam you enlarge the displacement and with that the total weight of the ship, and that should go somewhere