Flybuddy, look around for ANY 260B transponders out there. You won't find any. It's just not a feature very many people need right now, so it hasn't been at the top of our list, nor any other vendors. Releasing the 8 well tested, meaningless updates over the last two years (like having a transponder at all, the first of the experimental EFIS systems to do so, and with a device that can be upgraded by the user, in the plane, for free) has been at the top of our list
Heck, Garmin with the 330 isn't even saying if it can be upgraded at all to DO-260B, much less for free. We're doing or best. Get all your friends to call us and bug us and we'll move it up the feature list. It requires coordination with the FAA, EASA, and other people, and we can't just release it like we do other software.
It's still on the list, still being worked on and hopefully close.