For frag containers either of those (the amazon or Eric's) or the deli containers are "fine". The Amazon ones are very small, and regardless what the picture shows I've found they don't always hold water very well if tipped (don't tip your frags duh!!) , the larger ones are great because they hold more water and the lids are larger so you can actually see into the container regardless of frag information. Smaller ones are fine for smaller frags though, nothing wrong with them, and often are the more preferable method for the people bringing the frags if they're bringing lots of frags as the 16oz containers while great start to take up a lot of space and not everyone wants to bring a huge ice chest to a swap.
Smart & Final is a good place to get the deli-containers, do note that lids are a separate purchase. I picked up some of those deli containers at a Costco Business center which came in a 500 count box... so yeah I still have a few, the plan was to sell these off to people who maybe didn't want to buy 50 of them (which is what Smart & Final I believe sells), or maybe sell to someone who wants to buy 50 for a reduced price. Then covid hit, and not a lot of swapping of frags happened
To label them, easiest is just to put a piece of tape on the lid and write down the frag name, your name, and lighting. While you can write on the lid if there's any moisture you won't be able to write on anything else until your pen dries up a bit
Or just open up Excel print a bunch of small labels, cut them out, and tape them to the top. Lots of options on what to do.
