IKEA "Trofast Toy storage" used under my layout and I like it!
The small bins are 14-1/4", larger bins 13-1/4" as measured bottom inside - my measurements.
The most common review comments on the IKEA site is the plastic bins are not strong enough. I would agree and suspect storing heavy items for long periods would deform the rather soft bins. The optional bin lids have a recessed fit thate helps stiffen the closed bin.
I purchased the unfinished soft pine wood frame, which I finished with a coat of satin clear. Assembly was easy enough and took about 30 minutes. There are a lot of options including already finished frames, different frame types, shelf's, and clown colored bins. Popular items like the pre-finished frames were out of stock in the Portland IKEA.
My layout is expanding - adding room for dogbone and switching from MTH Realtrack to Atlas track.
