Hi PBB,
When I researched it, the only other company that I found that had another CDI box "in the works" was DYNA, who makes a lot of that type equipment for a variety of quads, etc. They did not have hard data about their box, and said they were actually doing it for a 'company' in the midwest. I suspect it was for someone like HPD or Hot Seat or something like that.
Most of Dyna's stuff is similar in price to the Vortex anyway, with less features. I don't know of anyone now who is making a bare bones rev limit raiser type CDI. I have seen a few of those type CDI's in other write ups, and they cost about the same or more than the Vortex anyway.
Good luck, and let me know if you find one...thanks,
JJ
le