Stands built to be aquarium stands are pricey. I've been looking around for an option that doesn't cost more than the tank, which for a Waterbox 20 is $270. Several threads on here discuss using Ikea furniture as a stand, or even just a kitchen base cabinet from Home Depot or wherever. All require some additional work to reinforce and stabilize them.
For my WB 20, I'm going with a storage cabinet I found on
Amazon, mostly because I wanted something taller (36") so I wouldn't have to bend down so far to look into my tank. It isn't perfect, and I'll have to make some mods, but it'll end up at about $150.
It's wider than the tank though, so if space is your main concern, nothing will be more space conservative than a stand made especially for your tank because it will be the exact width of your tank. It'll just cost more (~$275 maybe), but you can surely add shelves since your tank is an AIO and there's no sump needed.
Looking forward to seeing what you choose!
