A note on epoxy.  Surftech uses a sandwich construction (they are molded) for its Tuflite and wood series boards.  This creates a very stiff product.  Hand shaped epoxy glassed EPS foam surfboards are just as flexible as polyurethane foam polyester (PU/PE) glassed surfboards, but retain their original flex for the life of the board.
There are however, several shortcomings with hand shaped epoxy/EPS boards.  They cannot handle heat over about 150 degrees, as the foam melts at this temperature.  They cannot have transparent color work as the foam is too porous.  They cannot have a gloss coat as it must be out of polyester resin which does not bond real well to epoxy.  And they are much more expensive than PU/PE boards.