RE: Plank design info requested.
You should google images of Scott Hewitts "Mudda", which is a 100" slope plank, similar in appearance to the Zipper. VERY fast. In the Dave Reese video "Lift-Ticket" theres some video of it ripping up and down the coast in Santa Cruz very fast. A 3-meter one would RIP. Do you have any spots for DS'ing where you fly? Planks excell at it.