I'm just starting out with orchids and I've been looking everywhere for good S/H containers. I found some deli containers, but they're on the small side and the plastic is a bit flimsy. So, naturally, I looked at the stuff we had at work. I'm assistant manager at a small restaurant, where we use tons of stuff like this:
"Cambro" is actually a specific brand, but also a term we tend to use for the type of container. They come in a wide range of sizes. There are food trays that are quite small, up to the storage containers that start at 1 liter and go all the way to big buckets. The 1L ones are a good size for smaller phals and the like. I'm using 4L for my big Miltassia Shelob and Fdk After Dark. I plan on using some 2L squat ones for other houseplants like pothos and spider plants.
They come in round, and square with rounded corners.
There are half-height versions of most sizes, so you can have tallish containers or squat ones.
Oh and they STACK very neatly when not in use.
Some are translucent, and just a bit flexible (but still extremely tough), and some are totally clear and very rigid. The clear ones tend to cost a bit more. At a local discount restaurant supply type store (Kamei on Clement here in SF), the 4L round clear containers are about $8 each. A food storage container of comparable size at, say, the Container Store, is going to run you more like $15 and will probably not only be un-stackable, but less durable. Oh, and these are usually sold separate from the lids, so you don't have to pay for the lids if you don't need them!
Most have small handles, although the 1L to 4L square ones do not. They have a lip around the edge instead.
All have measurements down one side, which is a bit annoying, but not totally obtrusive. Some have brightly colored lines and numbers, while others just have slightly raised markings that are transparent.
They handle years of daily wear and tear in restaurant use. I don't know how well they will take UV, though.
I made a small tool from a piece of coat hanger bent into a triangle about an inch wide and 6" long, stuck into a wine cork. I use it to melt a 1" drain slit into the containers, heating it over a gas stove. They are thick plastic, so it can be a bit messy. I use a knife to trim off any extra bits of plastic that end up sticking out. A slit shape is nice, the LECA can't clog it, ever. I can put a thumb or a piece of tape over it if I want to fill/soak the container to flush it.
Search for restaurant food storage containers, and you'll come up with a lot of possibilities. Local sources might be a little tough to find, but you can order online.