Creating overlays / custom key kaps for cherry switches

[Harald]

I am currently working on a desktop calculator that will be using cherry MX switches (as they are used in a lot of keyboards).

Does anyone know of a source for custom key caps that fit the cherry switches?

The other alternative is to use caps from old keyboards and put overlays on them. If I go down that route, how do I best create the images for those overlays?
How do I print and cut them? Or maybe someone with the equippment for that would be willing to make a couple of those overlays?

Cheers,
Harald