I have gotten many great ideas from reading postings and thought I would share how I store my attachments. My garage is 16 x 24 with 12 foot ceilings. I installed 4 inch I-beams with trolleys and chain hoists to lift things up and move "stuff" around. Everything is on wheels and rollers so I can move things around and get equipment out when I need to use it. Most of the stands I built. I used hardware from harbor freight, menards, homedepot, fleet &farm, you get the idea - I cannibalized what I had to build the various carriers.
I hope you will find some of what I put together useful.