Freakmanultra

I've been looking for 2 hours and can't find my answer so I'm going to ask it here.
I have an 07 grand touring with nav and am planning on installing http://www.pioneerelectronics.com/PU...s/AVH-P4300DVD.
I really want to retain my nav voice guidance(voice is patched in at the Bose amp) but also want to replace the crappy bose speakers. I have read that you can install 4 ohlm speaker in the rear deck using the boss amp as long at the speaker is 4 ohms. So in theory I cound install theses speakers http://www.pioneerelectronics.com/PU...ries/TS-A6984R

Now for the front doors, what ohms is that amp? I've done many install in previous cars, but figuring out speaker Impedance always confuses me. I would love to make some mounting plates out of PVC and wire in some http://www.pioneerelectronics.com/PU...ries/TS-A1604C without having to run all new wires throughout the car(would loose nav voice).

Thanks for taking the time to read this!