Henni,
I have a midi guitar ... a really good one (Parkey Midifly) and I may be selling it and moving away from the chord control. email me to know more! Its a great guitar, all by itself and no interface is needed to make it control ALL the features (including sounds) of your arranger. Electric, acoustic and synth sounds - all at once, all controlled at the guitar - awesome instrument, but I'm going in a new direction.
Dave