Unicomp will do a fairly high level of customization by request, though not as extreme on the keycaps. However, Unicomp can and will do an entirely custom layout (using standard Set2 scancodes) if that's what you want as well. So if you want F12 to F1, they can do it.
Remember that Unicomp builds the keyboards and controllers, whereas WASD is doing nothing more than badging the base reference Costar CST-104.