xviper

Fuel line hose comes as a thick walled rubber tubing. Inside the wall (in the cut end) you'll see cloth strands that are woven in. As for the size, just measure the diameter of the nipples on your catch can and get a slightly smaller inner diameter fuel hose.
It will look very much like the hoses that's between your PCV valve and the intake manifold. All those hoses on top of the intake manifold are of the vacuum type.