Hi. I'm a newb here and have seen several posts about amps and wattages and cabs but none specifically for what I am needing. My current rig is a Fender Bassman 250 Head powering a Fender Bassman 4x10 and Bassman 1x15 cab. The cabs are rated at 8ohms. The 4x10 shows 700 Watts (Program) and 350 Watts (Continuous) at 8 ohms. The 1x15 shows 500 Watts (program) and 250 Watts (Continuous). The head is just a 250 Watt head. I know I'm not getting the full 250 watts when using both cabs. I'm wanting to upgrade my head to at least a 500 or 600 watt. What would be the best configuration needed for what I'm looking for? Please don't use any technical jargon as I don't know what any of it means. Just simple layman's terms will suffice. Thank you in advance!! The style of music I play varies from Blues to Rock to Hard Rock/Classic Rock. If that information helps in any way.