call Ken at Segway Composites. Im just finishing up a 12’6 he cut me out of his 2.5# EPS. The stuff shapes good to. He should probably be chiming in here pretty quick, if not, just search “segway composites”
Ask over at Walker Foam in Long Beach. http://www.walkerfoam.com/ They dont show it in their catalogue but they may have something in the works since SUP seems to be the new thing. Their shop is always brimming with foam blanks, fyi for other shapers.