can't exceed hp rating if u are gonna charter, was an issue for me on a 25 mako rated for 350hp, and was rigged w/ twin 200's. There is an argument to be made as older motors the hp was rated at the shaft, and now at the prop(or vice versa i forget), but for insuring a personal use vessel, an argument u won't win on a vessel for hire.
BTW that particular boat would have been a good candidate for a single 300 or 350 hp yamaha or suzuki as the mako 254 and 251 had slightly less deadrise than the 241 or 261 rated for 400-450hp for the deeper v. If i were doing charters not too far from home i would consider it for a 25 aquasport. If i were going more than 20 miles routinely i would go with twin 150-175's