If your looking for a good C4 thats completely built and ready to drop in, I would go with Performance Automatic. They have several horsepower levels to choose from, you could probably find one that meets your needs for around 1400-1500. Although i would highly suggest looking into an AOD instead of a C4 if your doing any kind of highway driving with the car. In which case i would recommend Lentech Automatics. The C4's are a great transmission when built right, but not having that 4th overdrive gear really makes for some loud, high rpm cruising on the highway. Also I would highly suggest getting a custom stalled converter for anyone running boost through an automatic, check into companies like Edge, Lentech or PTC.