I too am using a 200R4, and i did have mine built by Lonnie at Extreme Automatics. You may want to take a look at this if you are going to go with the lock up converter.
https://shop.bowlertransmissions.com...control-module I talked with Lonnie about it, he liked the idea and he installed it when he built my trans. Unfortunately i can't tell you anything about it from experience yet, still building the car.