We use large-ish plastic totes for almost everything. Clothing, food, camping gear, etc. They're plentiful, inexpensive, stack on top of each other and are reasonably waterproof to the point where if we need to set them outside they will keep the contents dry.
You can get them almost anywhere.
If you get transparent ones it's easier to see what's inside. We've been doing this since 2012 and it's worked very well for us.
They come in a variety of shapes and sizes, so if you want to get ones that are small enough to slide under your sleeping platform, you can.
My two pieces of advice would be (1) don't get totes that are too big, better to have two smaller totes than one oversize one and (2) get the kind with some sort of positive "latch" to hold the lid on vs the kind that just sort of "snap" on. IME the "snap" on ones will wear out and pretty soon even a small gust of wind can blow the lid off the box.
Are they rugged? Well, they're rugged ENOUGH. And if they break? Throw them out and get a new one, they're inexpensive. Having said that, we have more than a few that have lasted 10+ years of being knocked around in a truck or trailer and are still intact.