In my limited research thus far, Corbin and Baldwin are the two I have seen. I don't have either, so others will have to chime in.
Additionally, I know of another seat maker, Seat Concepts. I contacted them and they do not yet offer a Versys seat, but will make one based on interest.
If we were to shoot them several emails requesting them, they are quite responsive to wants.....I've been down this road with them on a seat for another bike (DRZ400) and they are a good company with a good product for very reasonable money.
**Sold**2008 Red Versys, Algard, LSL Frame Sliders, EvoTech Radiator guard, Givi screen, Givi V35 panniers, Moto Werks handlebar riser and footpeg lowering blocks, Aprilia Tuono mirrors, Carbon Fiber FendaExtenda, Spools/Sliders front & rear