Your torque converter stall selection also depends on the camshaft and other modifications done to the car. Where is your power band? You want the converter to hit the start of power band when you nail the throttle. However, I agree that 2,400-3,000 is a great place to start.
I had a precision industries 3,800 stall 9.5 inch converter installed in my '95 Z28. The car would "free" stall at around 3,000 rpm on the street, when you mash the gas, the car would launch at 3,800 rpm. On nitrous, with the higher HP/TQ output, the converter would stall at 4,400 rpm. When I ordered this converter through PI, I sent them my dyno sheet so that the converter would be a perfect match.
Mike