Need help with 95 Aurora

  I just bought a 95 Oldsmobile Aurora. It has a bose system in it. I want to replace the head unit and all the speakers. Well actually I would keep some of the speakers if I could and maybe just replace the 6x9s. I see on the vehicle information data base that it says i have 5 1/4 in the front doors and 6x9s in the back panel. I went to circuit city and they said I have 6 1/2 in the front. Anyway this car as more than just 4 speakers to replace. there are 2 tweeters on each front door besides the main speaker. and there are speakers in the bottom of the rear doors. Also between the 6x9s there is a small subwoofer. Im not sure of the size maybe 8 inch im guessing. I want to know all of the sizes and everything so I can order my speakers and do It all in one day. I bought the car stereo cookbook and read it. Before that I knew nothing about car audio. I am looking at getting infinity kappa speakers and a panasonic cqdfx983u head unit. Im not sure about the 8 " sub though. I would like to keep the tweeters in the front doors if its possible to wire them to the new front door speaker. I will need to get an amp for the sub also. any suggestions? I would like it to be able to push the sub and also give a boost to my other speakers. Any info is appreciated thanks.Colin Zito

Oh I was going to order from etronics.com. that is the cheapest place I have found on the internet. Do any of you have experience with them?Colin Zito