I know the blue ones can stack perfectly, I've got about 30 of them filled with everything from food to toys to books to school supplies in my basement. We used to use them to mail stuff to ourselves when we lived in Labrador and would go on shopping trips to the rock.
The clear ones are a couple dollars more, but they seem to be a little more airtight, have a lock latch, and have the added benefit of being able to see the stuff. They too stack really well.
Since they'll be stored in my pantry right now at a temp lower than the buggies grow at (according to a site I checked out) and the room is dark for 23.75 hours/day I wasn't too worried about light causing the grain to degrade. Just wondering if the light issue is one I need to worry about at all. The clear ones don't seem to have the plastic smell that the blue ones do, but if washing and drying works, I'll take a look again at the price difference. If it's only $20 total difference by the time I've got 10 bins of various sizes, I'm not too worried about that.
JW