I would recommend an older coach - a coach who knew the old technique and have also incorporated the modern game. He/She will be able to help you bring your game to a good level - without having to dismantle your game.
I remember, taking a lesson with a very young pro - very good player. But he was only familiar with modern game and wanted me to learn that from scratch and practice as if I am going to Wimbledon.
Then an older coach - who basically fixed some smaller issues added grip change - small changes - that helped me transition to the modern game. But nothing too dramatic and too quick.