Indoor drainage tray setup

[MCSchrum]

I grow my orchids indoors, under lights, on a steel wire shelving unit. On the shelves, underneath my orchids, I've constructed drainage trays from Sterilite plastic storage boxes, panels of egg crate louvers for fluorescent lights, and sections of pvc pipe. I'm sure most of you are familiar with this sort of setup. It allows me to water my plants indoors with a handheld sprayer without having to move the plants to the sink or the bathtub. After water I can just siphon the excess water from the tray into a bucket.

The storage boxes that I use are the Sterilite 41 quart underbed storage box. It's dimension are 34 7/8" L x 16 5/8" W x 6 1/8" H. This fits the my shelving unit nearly perfectly. The shelf's dimensions are approximately 14 W x 36 L x 72 H. So I have virtually 0 wasted space on each shelf. I plan on purchasing a larger wire shelving unit in the near future. The dimension of this unit are 74 H x 48 L x 18 W. I've scoured the internet looking for a storage box or a garden tray that would fit the dimension of the shelves on this new unit 48 x 18, but I haven't found anything yet. I know that many people use shelving units with these dimensions, but I'm not sure what they use for drainage trays. Does anyone have some suggestions?