I use the same primary color drawers that lalaland uses. I got mine at Target and they were advertised as toy boxes. There are 3 drawers in each one and you can attach wheels to them (they come with them) I have a whole bunch of them.
We live in a small house, so my husband put a fold down ladder in our hall ceiling. Then, he put down plywood and vynl on top of that over the attic beams. The platform is about 10 by 10. Then he turned a plastic bucket upside down and put wheels on it and a padded top so I can roll around and get into my stash. We don't have a high ceiling in the attic so I can't stand up. It works out great.
Verna