What is the approprite size of amplifier for my 2 new speakers with the following specifications; 150 watts RMS to 300 watts/speaker. 2 way design. woofer of 4 inch silver CD with rubber surround. 1/2 inch ferro fluid cooled mylar dome tweeter. frequency response of 37hz to 20khz. efficiency/sensesivity of 98 db @1 watt i meter. impedance of 8 Ohm.