If I remember, a ton of people were having problems getting DD recones because they couldn't prove they owned the motors or something? I don't remember for sure, but pretty sure I saw an epidemic of this happening a few months back on the forum. Maybe that's why he's doing it. Or DD recone pricing is raping him? Not sure, just a guess.
And to answer the question, I don't think you can get many other companies to recone the DD motors. AQ maybe, it is pretty close to the DD motorwise, but I'm not sure as I've never seen the insides of either :X