Hobie Cradle Install?

I just purchased a new Hobie PA 12. I'm going to pick it up tomorrow. Since I don't have cradles yet, I"ll be flipping it over and resting the sides on dense foam, resting on my Triton trailer kayak tree lower bar.This is just my way to get her home safely. I've been shopping online for Hobie cradles, to no avail. I'll probably leave that up to my kayak dealer to order for me. My question is, does anyone know a good and secure way to clamp these with a sturdy clamp to the rails on a Triton kayak/canoe tree? They are a little bigger than the Yakima or Thule bars. I can drill holes in the bar, if I have to, but I'd rather not. It's a brand new trailer.