6th Generation Maxima Stereo Upgrade help!!

[mitrals]

For the past couple of days I have been trying to look for a solution for my 6th generation Max without Bose. Here is what I am looking for: I want to keep the original cd player as I do not like the aftermarket look. Plan of action is to get a PAC NIS2 and hook up my zune to it. A couple of my speakers are torn so I figured I would change them as well. I am looking for some help in the following:

1. I am planning to get 6.5" speakers for the front and rear doors. Will I need any adapters/mounting brackets or is it a simple swap. Crutchfield says I will have to splice the cable for the speakers. Is there any available harness? Also will a 4 ohm speaker do? I know the Bose system is 1 Ohm but I donno what the non bose speakers are.

2. The rear deck. This is where I am confused the most. Does my car come with a 6X9 or 8" subs? My plan is to replace them, get an amp to power them. Brings me back to the head unit: I do not think there is a line out. Should I use the wires that are going into the back speakers or should I buy a line out kit from PAC? I am not looking to add a sub box. I wanna keep the install as clean as possible.

Also are there are tutorials for me to open up the panels/console/rear deck? I have been finding everything for the 4th and the 5th generation.

Thanks for the help.