In addition to whatever requirements you may find through the USDA, keep your own list of things that would be good for hedgehogs (which is likely to go above and beyond what the USDA requires).
For example, I know some folks have used wood... Looks like you've already figured out needing to address the urine issue. Think, too, about mites. It's going to be a real pain in the rear if you ever have a mite issue. Given the way that mites seem to crop up on hedgehogs, some theorize that, to an extent, there are always mites on hedgehogs... And it's only during times of stress/illness that the balance get out of whack and you end up with an outbreak. I mention this because the old thinking that goes: "well, they don't have mites now, I run a clean shop, so I'm not going to ever have issues with mites" just doesn't pan out with these little guys as well as one would hope. So, it certainly doesn't mean that it's impossible... just make sure you're walking into it with your eyes fully open.
Given a couple illnesses my hedgies have had and the amount of cleaning needed to ensure health... ugh... took a lot of time and energy. But I had the relative ease of being able to clean plastic... I think I'd cry if I had to ensure that wood was fully free of issues.
Actually, C&C cages are pretty popular among the hedgie crowd too. I don't happen to have them (I prefer the wire-top, plastic-bottom version because I can use a CHE set-up). You are absolutely correct that the openings on the cubes are definitely too big - both babies and adults can slip right though them. As long as you get the coroplast to go up the walls, that may be a better choice than wood. It's not going to harbor mites, you can wipe it down easily enough with the big scary things like bleach (then rinse the dickens out of it, of course!), etc...
Tanks -- like the glass sided fish tanks -- aren't really favored in the hedgie community. Not enough air circulation is the main issue there.
Other question: how are you planning on heating your new cages? The type of cage will dictate heating / the type of heating will dictate the type of cage. If you're flexible on both ends, you're in a good place. But if one part of that equation is fixed, then the choices on the other end are narrowed.