Thats the way I'm going, From what I have seen and heard about Lewis and his products leaves no doubt in my mind which way I'm going. Quality products with a quality person equals satisfaction in my opinion.
I did the Polk upgrade from Lewis last summer....the fronts sound much better, and adding rears (where Honda forgot to put speakers ) made a huge difference. I can hear the stereo just fine when cruising along. I know a lot of folks swear by the amp-install to get "good" sound from the system, but the open air is not a decent sound-stage to begin with. Very satisfied with the product and the service from Lewis.
Go for it...you won't be disappointed! (You can always add the amp later, if you decide you need it.)