Looking for High End Car/Truck Audio Dealer in New England

I'm looking to replace the original sound system in my 2017 F250 Super Duty with high end equipment.  I live in Maine but will travel as need be--will go to Boston if that's what it takes.  There are lots of dealers up here; but they mostly all carry the same, B-grade aftermarket stuff.  I'm looking for the real deal, and real expertise.  

Any recommendations greatly appreciated.  

John