There's nothing like a Professional. The Pro took the keyboard world by storm because of its simplicity of installation, swappability and modifications that don't require a soldering iron.
This is an excellent illustration of an modular keyboard
A word of caution: it could make you sick, I was a keyboard player, me, as well through the maze,
It's a bit odd to think of buying an already-built keyboard is an old-fashioned idea Simply removing another keyboard could be a violation of the warranty but it's not.