Generally you'd want a torque converter to match your turbo & application (ie. city/ highway driving, drag). So, if you still have the stock turbo & street tyres the 2800rpm stall would be better suited as, the stock turbo will start to build boost at around ~3000rpm. Also, note that with most turbo engines the converter will have a flash stall higher than 2800rpm, so when launching it will be more like ~3300rpm.