Congrats!
126mm mags. I prefer the STI Tac magwell. I'm sure there are others that will also work. And I also prefer the International basepads (wedges) from Dawson.
And yes, you could trim down your Edge, mill a light rail and install a bushing barrel. Pricey project, but I'm not exactly the voice of reason, so don't forget the aftermarket aluminum grip too!