If you haven't done any shaping before a good way of learning the skill is to first cut out your board/outline.
Then with the scraps of EPS try & shape a model SUP, it will require the same steps & probably more care to do it well, light grade EPS is **** stuff to shape, it will take practice.
And it is a little more work, but less expence to shape from flat sheet.
Shapers below sell EPS blanks but they are pricy, particularly if you stuf it up!
Just remember its far easer to take more foam off than to put it back on

For info on the subject of shaping & glassing see www.shapers.com.au for DVD's
9' x 27" Shaped The 8' x 26" next
The rocker is close "un bent"
Concave deck full length, reduces weight, c of g & full buoyant rails
The weight of glass & resin will nomaly make the board slump to the support that is setting the rocker, or a wood screw either end to pull down