I added some much-needed storage to my shop this past week. 8' high, 8' long, and 24" wide. If they would have had 10' uprights I would have gone that route. I had a smaller shelving unit (in front in this picture, waiting to be re-purposed elsewhere) sitting here but couldn't find anything remotely sturdy to add on so I decided to just start over. It takes up some dead space in the shop without interfering with my TS work space. And it eliminates a lot of stuff that was sitting on my benches, the floor, and mobile carts. Purposely bigger than I need so I have room to put in-progress projects somewhere out of the way.
I used "Gorrilla Rack" components from Menards. They aren't exactly heavy duty pallet racking, but work well for this purpose. Its bolted to the floor which makes it very stable.
I think I'm going to bolt a piece of plywood to the end to give me some extra wall space to hang some stuff up.