Commercial Midi Pedals
Below is a list of commercially available organ pedals by various manufacturers. 
 

Classic Organ Works:
This AGO pedalboard engineered to the exacting specifications of the American Guild of Organists for a 32-note pedalboard. 
More Details

R.W. Designs
The Consoleete Pedals has individual note spacing exactly follows the B-3 flat-radiating 25-note pedalboard. 
More Details
Hammond
XPK-110 13-note MIDI Pedalboard is exactly like the classic M3 Pedals.  
More Details
Roland
PK-5 13-note MIDI Pedalboard 
More Details
Roland
PK-7 20-note MIDI Pedalboard 
More Details
Roland
PK-25 25-note MIDI Pedalboard 
More Details
 
Studio Logic 
MP-113 13-note MIDI pedalboard
More Details
Studio Logic 
MP-117 17-note MIDI pedalboard
More Details