I stopped by Walmart today and got the Plano 2-3650. It's a one-shelf tackle tray (just starting out, so don't have an abundance of accessories/cartos yet) that is modular and fits inside a stackable tackle box.
In regards to labeling/marking the cartos, I bought a couple of $1.00 packs of star stickers. The stars are small, and come in yellow, red, orange, purple, and green. When I get a juice, I'll put a sticker on it (say red). The cartos with that juice will also have a red sticker. I can mark on the sticker, even though they're small. I can put an L on it to indicate LR. Since I'll have more juices than colors, I'll make another identifying mark on the star, such as a slash through it, or perhaps a number.
So, I've got two juices with red stars on them. One bottle will have a numeral one on the red star. The other will have a numeral two. On my atty, I can easily find the right juice by matching the stars. And I'll be able to tell which one is a regular resistance carto, and which one is the LR by the marking.
It looks ok on paper..... we'll see.