Suzuki 4WD Club of Victoria

Going to make a workshop trolley, the kind you put all your tools on when you can't be bothered to put them away properly and when you find something like a washer on the ground and think "better save that" and just chuck it on the trolley too.
Thinking of having a conductive top maybe with clamp points and no sides so I can lay stuff across it then maybe a tray (bottom bunk) below.
Any ideas guys?

Take a look at this video. Some real world ideas.
https://youtu.be/gqJtbaBoeXI

It's just a fluke it's the same height
I was looking at some on eBay for like $65 but there were 350mm wide and that was weak but now idk what to ma the trays out of