SinisterSlim

I’ll add CannonKeys and Mekibo to the list:
https://cannonkeys.com/collections/gmk-keycaps
https://mekibo.com/collections/gmk

3" x 5" index card boxes from Walmart for both keycaps and switches. They’re stackable and each box will hold 200 switches or a full keycap base kit. It’s wide enough that the spacebars can lay flat too.