The amp you chose is 600 watts rms at 2ohms and the subs are 300 watts rms but thats at 4 ohms. You need to find speakers that match the watts rms and the ohms. Also remeber when speakers or voice coils are wired in series, you add their impedances together to find their total impedance. Two 4-ohm speakers wired in series have a total impedance of 8 ohms. When speakers or coils are wired in parallel, however, the formula for their total impedance is more complicated. When the impedances of all the devices are the same, their total impedance, when wired in parallel, is that impedance value divided by the number of devices. For example: four 4-ohm speakers wired in parallel have a total impedance of 1 ohm.