I guess if you're going all explod.. then why not match up the Xplod amps to the Xplod subs you are getting. I dont know the specs of the "top wattage" subs... once you get that info... match up the "RMS" wattage with a simliarly powered US acoustics amp, JBL, etc.
I guess there were bound to be fans of Xplod out there somewhere. Hey if it sounds good to you then :thumbup:
*edit* uh... how did you fit 6x9s in the front doors of your car? I think you probably mean 6 1/2s for the fronts...