New gaming keyboard many of them allow multiple key maps.
Logitech G15 or G19 perhaps or the part keyboard for the left hand such as the G13, the Saitek Cyborg is another.
All of those are corded though there are cordless, check out the specs and see if they do what you want.
I think overall its the easiest way though they are not cheap as keyboards go so be prepared to spend £70 +
|