I'd go turf tracer, 23 Kohler or Kaw,52 or 60" Ultracut deck, 200Lb clutch, bigger tires,bigger bearings. About 6,000Dollars This will do comertial very well.
All or most of the parts are from the lazer z. You will see in the picture that they are brother and sister.
John
Oh go into search Look up--------- To exmark------- And that will answer why you need the ultracut deck that comes on the turf tracer.