If I understand you correctly, your Kicker amp is powering two separate sets of component speakers?

Not sure about Kickers, but my Infinity Kappa perfects require 100 RMS each, and my Polk DB's want 90 RMS. A more powerful amp would definitely give you the sound your looking for.

At the volume level your getting distortion, it sounds like you might have your input sensitivity set incorrectly. Read my post here if that is a possibility. If that doesn't help, you could disconnect the rear speakers for the time being and bridge the amp to your fronts.

Now if your looking for a sub anyway, I would use amp you have for a Kicker CVR 10 (or something similar), and get something around 400 RMS to your components.