Since I first posted this, I bought a used working Kenwood monoblock amp from eBay (120 Watts, $21.50 shipped) and installed it this past weekend under the driver's seat. Since I had to pull my shifter console cover anyway in order to run the 6 foot long preamp wires from the amp to the head unit, it was actually easier for me to tap off the cigarette lighter for my amp turn-on power. I accessed the RCA preamp out plugs at the rear of the base Pioneer head unit by first removing the glovebox. That way I did not have to pull the head unit.
For right now I'm using an old 6x9 car speaker in a sealed box. However I just bought my 8" Rockford Fosgate sub from eBay last night. When I get it installed in a sealed enclosure under my front passenger seat, I'll do a webpage write-up.