If you have a hull, then the main issue is to fit the deck within the bulwarks. I assume you have a set of plans, otherwise you are flying blind really.
As far as construction is concerned you need to fix a supporting structure within the fibreglass hull to sit the deck on. The usual method is to fit 'stringers' around the inside of the hull which the deck will sit on and these are normally connected across the breadth of the model by deck beams. The deck will need hatch cutouts to access the internals.
If you are intending to have a working model then you will probably need to have a weighted false keel to balance the model when afloat.
Others on here are better qualified than me to describe how the sails might be controlled using R/C.
Colin