got it i will start with the dash then and go from there
I replaced all 6 speakers with Infinitys. I did the dash first and while the sound was great, it was very overpowering at first due to the speaker's lower resistance and higher sensitivity. Fading the audio back to the rear a notch or two helps.
For both sets of 6x9's I went with the 2 way speakers. There is a button on the tweeter portion of each 6x9 that gives a 3db boost to the tweeter. I turned this off on all 4 speakers. In hind sight I could have left it on for the rear 6x9's. The front gets enough highs from the dash for my taste, so I wanted more bass from the 6x9.
Last thing I did was add the resistor from Infinity to the dash 3.5's. In the stock 6 speaker setup all speakers receive a full range signal as previously mentioned. Whenever I cranked the volume it seemed like the 3.5's were really struggling trying to hit the bass notes and I thought they may blow.
All in all, its a night and day difference from the stock set up for not a lot of work. The 6x9's wont give you any"bump" but do have a good bass.