See if there's an Industrial Paints and Plastics franchise in your area. They'll have some.
http://www.ippnet.com
Another option is fibreglass rods. Again, IPP will have it but if you can't find them I think I heard you can get fibreglass rods at Canadian Tire. GreenSpottedPuffer found some there (I guess they are parking poles or something?) .. here's the post (with some pictures):
http://www.canreef.com/vbulletin/sho...67&#post278967
And I've heard of someone using fibreglass arrow shafts.
Good luck!