None that I know of and if the Z Wing sales this year is any indication, I doubt that there will be a stampede of other makers rushing to follow suit.
It has not sold well. It has had problems with the Z Wing mechanism such that they are redesigning it. Additionally the frame and overall width does not provide an excess of stability for a 48" deck.
If next year, the revitalized unit catches on, then maybe there will be some copy cats, but for now it is the only choice of it's kind. Also the engine that is used is the same one that they use on their high end residential unit and I'm not sure that it can be considered a commercial engine. At least they are using individual pumps and wheel motors.
My thoughts on it are that if you have a 36" gate to deal with, it is probably on a small lot and a small mower should be adequate for the job anyway.