I'm up to 46 bins that are at least 64 qt size. There are certainly ones I have that are larger for longer rockets. Most are lain horizontally.
Each bin is numbered, and it's contents are on a spreadsheet. When I build one, I just put a 'B' beside it. With the number of kits I have, I try to be somewhat organized! Really helps if I see something I want, often I have to check my master listing first to see if I have one already (or 3, etc.).
Manufacturers are in alphabetical order. The kits then have a corresponding bin number which makes them easier to retrieve.

Allen