I teach high school woodworking and love challenges like this. We don't have enough snow in Middle Tennessee to warrant such a sled but I read several articles on building a pulk after seeing your blog.(never had seen the word "pulk" before today) After looking at the $495 and up price tag from the retail side versus the skipulk.com site for build your own why not give building one a shot. They suggest the best pole is flex pvc used in elk ranching. Used pole vault poles would also have the same flexiblity and tremendous strength. It would seem that a really good sled could be custom made for around a hundred bucks.