That amps shows to be 2 ohm stable (as long as its not bridged) You could just parallel your rear 6x9s and 4's and you wont need another amp.so I need an amp. I was thinking this one for the 6x9's and fronts Sound Ordnance™ M-4075 4-channel car amplifier — 75 watts RMS x 4 at Crutchfield.com
and maybe one for the 4" speakers.