I get the question a lot from fellow Army guys who want to get the commercial-add on to the Comm-Rotor. There seems to be some confusion, and I am glad Wasp brought it up about what is required. Anything that is category specific is all that is required (i.e. in a SEL / MEL airplane). If one gets a like person, my suggestion, in order for it to be cheaper on them would be to get the PPL-ASEL first, build the specific category time solo, then come back and train for the commercial when they are within about 10 hours of the minimum requirements. This has seemed to work well in the past.
Just my cent-and-half...
CD