Ah I was thinking of thin flat strip of wood. Thanks for the warning. Then wood and metal are both ruled out. I would love to build a crate rig like the one you pointed me to (thanks) but I just don't have the time now + my need to be operational is more urgent. Once I am operational, I want to take my time and build a proper rig.

If we are looking at rod shapes, can I use think plastic pipes used in plumbing? I can figure out a way to secure the rods to the case, what about the gpu to the pipes. Should I do that too?