I am getting ready to purchase an SWR Goliath III cabinet. This thing is rated at 700 Watts RMS. Which is better the 4 or 8 ohm model? Also, I am leaning towards a QSC PLX power amp or maybe a Carvin DCM power amp. Which model of PLX would give me plenty of punch to get though the mix? I am not worried about loudness, I just want plenty of punch and I don't want to tear up the cabinet in the process. I have read that underpowering can be as bad as overpowering. I play with an organ player and guitarist as well as the drummer and punching through the organ is a must. Any thoughts on the ohms or power amp? I am new to this as all other setups have been combo amps. Thanks!