Hides: um, good idea to check measurements before you order hides- R.B. gives you the dimensions, but they cannot force you to double-check what you're ordering.

Coco. husk: I've never seen it in a hardware store, other than maybe in garden section, but it might not be safe (ie. without contamination) for pets. I'm surprised your local pet stores don't carry it, but if they did, it wouldn't be cheaper there. Have you tried online suppliers such as Chewy.com or Petco.com? Pretty sure even Reptile Basics sells it? https://www.reptilebasics.com/substrate

(I have bought huge bags of orchid bark from a florist supply, & also a plant nursery, but these places may or may not know whether it's safe for your use with pets. Reading actual packages might help, if it's well-labeled.)