I made the these wooden stands out of inexpensive wall studs and painted them. They come apart, the middle section lifts out.
I also put together the C&C cages all by myself, so many zipties. I think the top structure is the longest 2-story I've seen - 10×2 grids, plus the offset loft. I spent a long time brainstorming where and what kind of doors and lids and stuff to use for best access to all the levels. It is surprisingly easy to clean out and I can get all the coroplast out easily too.
I'm planning on expanding it further, going to make it go off in an L-shape I think. Still drawing up ideas.
Oh and I built a matching hay bin on wheels, looks a mess right now though... it really only holds like 100 or so pounds of hay and I tried to stuff an extra 100 pounds in yesterday on top of that. They had some nice Bermuda hay at the feed store for only $18!