@55 did loose some on the high end heh, it's not loudness, its the headroom to drive all 4 cabs, when I turned up the volume the sound thinned out(farted) I was also thinking GK fusion 550 for the 8/10's & slaving a RB1001 for the 2 15's all cabs are 4 ohm.
SWR makes a 750 watt dual amp head...