front OEM speakers power rating?

Alpine power pack should be plenty - 45w rms

Alpine KTP-445U Power Pack Upgrade any car radio to 45 watts RMS X 4 at Crutchfield.com

Clarion makes a similar product but the RMS ratings are slightly higher

both can be affixed behind the head unit (factory or otherwise) and concealed in the dash

^ crutchfield is also currently having a sale on all alpine speakers (buy one pair/sub, get another half off)

I know it was ur goal to maintain the factory speakers, but i have always been told that the Type S speakers are decent and a good improvement over most factory sets; they are good without an amp, and most likely even better with a small 4 channel. just something to consider. you can get 2 pairs (one coaxial set, one component set) for under $200.