Jason
There are a number of ways we build our stands. For me, I use a set of calipers to measure the hull beginning at its widest and then transferring the measurement to an old cereal box. Cutting a pattern from a cereal box is best and getting it right before cutting it out of wood.

If the have the frame plate for several locations along the hull. Then trace this pattern to the cereal box, cut out the pattern, trying it and trimming off excess till you get it the way you want.

Remember to allow about 3/8” of an inch all around to place the rubber padding that your boat will rest on. I use the foam pipe wrap found at the hardware store,

Hi
I have built a tug using standard ply keel frame and deck, then glued extruded foam between the frames keel and deck to complete the shape, after smoothing I have glassfibred directly onto the foam using west system Epoxy resin - which does not destroy the foam. This makes a very solid hull, which is virtually unsinkable. The foam is from packing saved for this purpose. I am now building a second 46 inch tug using same system.

Ralph

Have not tried this method personally but do know others who have had success. I believe you may have yo cover the finished foam shape with some form of protection (parcel tape may work) otherwise your shape will dissolve before the resin sets.
Assuming you only require the one hull this may be th quickest method but I suspect you will need quite a bit of rubbing down to achieve the required finish.
If you are considering multiple copies your former is unlikely to survive the removal from the hull.The traditional way is to make a hull and prepare a mould (usually in two parts) and lay the fiberglass in the mould on top of a gel coat. Takes some time but the end result is repeatable.
Good luck with your project, perhaps you will start a build blog to share your experiences 😀