I'm new to cabinets and heads. I've been playing an ampeg BA115HP combo with my band for the last few years and now I'm looking for something alot louder for when we play shows. I just picked up an SWR 4 x10 cabinet and i just assumed i should get a 400W head, but i guess thats not how it works. The guy at the store told me a 100W head would be fine. I tried the 100W head and it was loud but i wanted something louder, and i know that soon i will buy and second cabinet probably also 400W. So, with that in mind, my questions is what should i be looking for, as far as wattage goes, as a head for this cabinet. If you have any specific suggestions of models feel free.