AFS is owned by Dynon and both systems can use the Trig TT-22 (remote) transponder. Add the Dynon ADS-B GPS-2020 antenna and you are set for OUT for less than $600. Lots of portable, low cost units available for IN (e.g. Stratux).
I have the above with Dynon's ADSB-470 for IN and love the functionality. Once they work the bugs out of the newer 472 (uAvionix hdwr inside), I'll upgrade to it via their trade-in program.
It would be nice if they worked with the uAvionix stuff for OUT but I understand their desire to make a profit with their own products.