I wanted something that offered protection from dust and lint, but that I could see into. Because I also lower the frame at times, it couldn't be tall storage containers. Something reasonably attractive as well.
The Sunday paper had Michael's Arts & Crafts sales ad and the Jetmax Modular Storage units were on sale. I have one of these units in my sewing room and it has stood up to sliding the drawers in an out countless times, and the weight of thread and other items reasonably well. Not much wear at all.
This picture is of the open cube on wheels for the pantographs.
Here are two of the units under one side of the frame. No more wasted space under the frame, and some nice storage.