You'd be better off making your own snowboards rather than using surfboards as proxies. Sorry but the shapes are completely different and would not look right.
Just get some plasticard, cut about a 1.5cm by 2.8cm strip, heat the ends to bend up the nose and tail of the board, (dip them in cold water to set the angle) then use a sanding block and work the curved nose and tail. Add bindings and a backfoot leash to taste, maybe a stomp pad between the bindings.
Definately a market for this genre....