In case it's helpful to others, it does seem like they're pretty available now. The wait time was a week or so longer than quoted, but it was still wasn't bad.
Just installed a skyBeacon and did my test flight for my ADS-B rebate. The determining factor for me was the fact that (at least one avionics guy I talked to--but not the person that did the skyBeacon) my Narco AT50 didn't have enough output power to drive the GDL 82. If that's accurate, I would...