Though I don't use it for csound, the Peavey PC1600 is by far the best MIDI
slider box.  16 sliders, 16 buttons, and a wheel.  Any MIDI string can be sent
from any slider or button.  Also, two control voltage inputs which you can
hook pedals or home-built electronics into.
-- 
Mike Berry
mikeb@nmol.com
http://www.nmol.com/users/mikeb