Aquarium stands are designed to support hundreds of pounds of weight, and they’re large enough for most CRTs to fit comfortably.
I use the metal “imaginarium” brand from Petco, and they’ve worked phenomenally for my Sony Wega 32FS320: https://www.petco.com/shop/en/petcostore/product/imagitarium-brooklyn-metal-tank-stand-40-gallons
Just be sure to measure your CRT’s dimensions before buying so that the one you get will fit.
This is very clever. I have my Crts all on big metal racks, but if I were going to just have one, this would be the way to do it.