there was a thread a while back where we talked in depth about how to build your own cradles. You should be able to search for it. Briefly a couple of them were:
A) w/ boat upside down, lay copious amounts of plastic on hulls, cut a piece of carpet and lay fuzzy side to hull, fiberglass the heck out of it, fiberglass a wood block to backside once that cures and bolt to trailer.
B) get some of the big thick wall PVC, cut in halves, heat in oven to make it soft, lay on upside down hull and let cool, coat with carpet.
C) go buy some.