HELP installing speakers :(

[camaro99]

Hey guys,
I'm new in car audio. I need some help in installing door speakers.
I have 1999 camaro. I took the panels out and saw that the factory speakers have no marking for what watt they have. Also it has dual voice coil and two pairs of wires are in there. The speaker (kicker) i want to install has single voice coil. How do i install it? Can I bridge 'em or just use one pair and tape the other one?
Another question is, if I want to run the door speakers with an amplifier, how do i wire them? Do i have to use the speaker cables that's currently in my head unit going through the factory amp or there is another way?
I heard about PCM and grommet in the firewall, but i'm not sure how it looks like. Does anyone has a pic that I can look where exactly to look and put the power cable through?
I don't want to use the trunk for speakers, but there is no stealth boxes make for Kicker solobaric.
So i'll put one 12"L7 behind the back seat over the tank powered by a kx600.1 amp. The dimension of the box will be 9*14*22 inches with 1.11 cubic feet. Does it sound like a good plan
Thanks a bunch to all of your support.

[mstereo]

Call me at my store in Bentonville, Ar. and I'll walk you thru it.
It would be easier than typing it all out.

Ask for Craig 1-479-271-8800

[camaro99]

thanks will try to call