I think it was a keyboard by Quasimidi--maybe it was the Raven (but I think that was another keyboard) or maybe it was "Serius"--that had a built in mike holder with mike. It was not an arranger, but probably had a vocoder built in.
But several keyboard stands have provisions for mike booms--this might be a more productive line of search.
[This message has been edited by Clif Anderson (edited 02-15-2002).]