Although I'm playing this piece on the Caen sampleset I cheated a bit. I am using Hauptwerk's built in octave and suboctave couplers to play this on the Positiv with Recit coupled. Uses the strings and undulating stops, with tremolo on and 32' pedal. It was in an attempt to ward off temptation to buy some of Sonus Paradisi's new samplesets which I can't afford - I'm still paying off Caen!