Witness
From EAA web site
You can easily convert your Witness steel or polymer frame pistol to shoot .22 LR, 9x 19mm, 10 mm, .38 Super, .40 S&W, or .45 ACP.
Available in 9mm, 10mm, .38 Super, .40 SW & .45ACP Optional Conversion Kits - .22LR, 9mm, .40SW, .45ACP, 10mm MSRP $472 - $514
I think that you can convert anything to .22, 9 to 40 and vice versa, and super 38, 45 and 10 to anything. not sure about the super 38.
Same thing for the compacts.
I have a steel wonder finish full size 9. Shoots great and always works. I'm trying to find the 22 conversion for this pistol. That's how I want to have some more fun - shoot a whole lot of cheep ammo.