X-keys makes their matrix board. With some tinkering, you can "make" your own Xkeys to any layout you wanted.

In theory, with a 3d Printer, you could make a real professional one.

But that one above.... is pretty unique!

Not sure it uses X-keys driver boards though you can see a Pro in the background.

http://www.boingboing.net/2007/05/28...-keyboard.html