Are you currently connected to a metered water system? If so you may be able to estimate the water flow while the sprinkler is running. Most sprinkler heads are also rated by gallons per minute. A little homework may get you your answer that way.
You will probably want about 50 psi pressure to make the system work well. Once the flow and pressure is established the pump selection is fairly easy. With a 2" well, you will use a jet pump. I am not sure whether or not in your area the jets are installed in the well or suction is applied directly to the the well.