I would recomend you to look at Ship Constructor from SSI corp. It is a AutoCad based software purpose made for ship building. ..but I have...
MS Valö and MS Rivö, built by Bröderna AA (www.braa.no) are built in CRP and hold full certificate. They have a LOA of 27 m, takes 163...
General Design: Rhino
FEA: NE Nastran /FEMAP
I can only speak for the stability parts of RhinoMarine, compared to AutoHydro. For small boats it might do, since its easy to use, but...
To assist you in the area around the towing winch I qoute what DNV states in their rules what loads to apply. Basically it says that a SF of 1.25...