Forgive the absolute flaming chaos mess, I've been a little under the weather the past three days or so and have only bothered tidying the *inside* of the cages where the piggies actually live, lol. Priorities.
I built simple wooden stands out of inexpensive wall studs. This serves the dual purpose of freeing up a ton of storage space underneath, and keeping the piggies above the level of my dog's face so he can't easily pester them. (He mostly just likes to watch them, but they aren't big fans of that!) I have a hay bin on wheels underneath that I also built, it fits 50 pounds of hay. When it rolls out it has a work surface for cutting up vegetables.
The main con of raising the cage more than one grid level is that you have to think about how you are going to reach to clean. I have a dedicated stepstool for that, and when I need to scoop up a pig, I stand on that small green table pictured. But other than that it's very nice, all my pig stuff tucks away under there, when I organize it properly anyway.

The pigs also seem to get a kick out of being closer to eye level with us.
So that's an option to consider if you are even a little bit handy and want more storage than a typical cage stand made of grids can provide.