I would like to add an auxilliary fuel tank to my 24' Wellcraft sport fisherman walkaround. I'm thinking of a plastic tank (Folt) rectangular in shape (50x13x12 30 gal.) I would like to replace the existing transom board with a structure to house the tank that would also serve as a bench seat. How should I plumb it? Will there be trim problems with the weight? other comments! thanks