Tomorrow I am buying a SM900 head after some solid research!! I am also picking up a Goliath III cab to go with it and i wanted to know whether i should get the 4 ohm or 8 ohm model. I may at some point (after saving more money or if needed) be getting a second goliath III or maybe a Son of Bertha to go with it. Knowing that which one do you all think would be best? I know with the SM500 it was recommneded on here to get the 8ohm and run it bridged mono mode if i was going to add on another cabinet - thank you SecretDonkey. Because the 900 has more power....does that still apply? I feel like an idiot asking..but Im just starting to learn about this stuff. It looks like the 4 ohm is the way to go to me....but again...im just learning.