I work with several guys who have Snap-on boxes with sliding drawer trays, so I assume other big brands also offer trays.
Making custom trays is not a huge job, or ask your local high school metal shop/FFA about doing it as a class project. My neighbor's boy made a 4x8 flatbed trailer in shop...
Thanks RedVise; love the RED lining!
It's not that I don't like the usual green lining, but something about red felt and a nice warm wood color...
I made this box in the late 70s, Jr. Hi shop class. It's been my "treasure box" ever since.
My avatar is "Smokey," my 1982, K10, 6.2 Diesel.