wire racks sturdy enough to hold tanks?

They looks a lot like the Nexel black epoxy wire racks. I have used them before and have heavy bioactive tanks on them. It is possible the target one is a less robust version, but I doubt it is specially made for better or worse.

Assuming it is the Nexel rack, they are rated to 800 lbs a shelf on that model. See here.

Thank you so much for this thread and the photos of different examples! My husband and I have been going back and forth on how we want to upgrade our tanks. After looking at this, we bought a heavy duty shelving unit with solid metal shelves. Our plan is to either put PVC cages, Exo Terra terrariums, or combination of the two on the shelves. :)