You need to talk to the manufacturers and give them your information on the engine, car, trans, gear, and tires, and what you want from the converter.

I had Ultimate build me a tight street/strip converter. It is a 9" 5,000 RPM flash stall converter that is so tight it seems like an 11" converter until you really hit the throttle. It is exactly what I asked them to build me, but it was a bit pricy, just over $1K plus shipping.