Actualy, the 9600pro IS the greatest overclocker. its not the fastest, but it oc's like mad. Ramsinks arent necessary. My friend has 0 case airflow, and only gained about 10mhz with them. With any airflow at all they should make no dif.
For the core, it makes probably hte least heat of any modern card. My friends survived a whole day with nothing on it. If yo want to keep the modding to a minimal, look for something copper. If you feel like modding, get a 1u copper cpu sink.