Welcome to the Forum Rich,
There are not very many working, 'ready to run' sailing model ships out there and you have done well to find that example from Cornwall Model Boats.
Large sailing ships such as Victory or Cutty Sark don't make very good working models as when you scale them down the sail area reduces by the square root while the displacement (weight) of the model reduces by the cube root so they very soon end up carrying an amount of sail that is totally out of balance with the ability of the hull to support it. Basically they fall over! Thames barges represent a compromise which can give an acceptable sailing performance although they will often require an external keel to offset the pressure of wind on the sails.
Thames barges are not too difficult to build and we have an expert on the forum, Kim, who can give you much better advice than I can.
I am afraid that, realistically, you will have to rule out any idea of building a working model Victory or Cutty Sark.
MyHobbyStore offer plans of the Tea Clipper Ariel **LINK** as a working model but this does require scratchbuilding expertise.
Colin
Edited By Colin Bishop, Website Editor on 15/09/2014 19:30:00