Ladder rack

I'm considering a job where I would need a ladder rack. And for more than just a single ladder, probably several long boxes as well. The weight would be substantial, but within the Prius's GVWR.

I got to thinking about the tow hook points in the front bumper, and I have a hitch in the rear, does anyone know how much force they can handle at a 90-degree angle? (i.e., the hitch is rated for 200lbs of tongue-weight, would the tow hook points be able to handle similar?)

 

Well, the folding ladder I already have, and that I would just throw in the hatch, since I made a flat replacement for the rear seat/cargo area.

The real wrinkle is carrying 14-16" garage door sections. I'm planning on just welding together a custom solution, but I'm unsure of the vertical load I can put on the tow points.