Jbl Stereo system noob

Ok guys I need some help on installing a system in my 2006 Double cab.
My truck has the jbl system in it. What I need to know is that if I remove the factory amp and sub, do I then have to rewire all the speakers to another amp or can I just run new speaker wire the the new deck? From what i have read, if you removed the factory amp and sub you lose all power to the door speakers is this true?Then since I'm pulling the amp and sub out do I still need to order the stereo harness compatiable with the jbl system or just a regular tacoma harness? Im going to be ordering the harness from Taco tunes. Its going to be 170 for the stereo harness, steering wheel intergration kit, and stereo bezel. I found a loaded box with 2 c10 kicker subs from hifi audio for 200. Please give me some advice or tips before i start to go install this mess and end up not having what I need or proper harnesses. I'm fairly savy when it comes to installing aftermarket systems. I just never have messed with a vehicle that has factory amps in them.

 

Bump. Come on guys I don't want to spend an extra 80 if I don't have too

 

Anyone

 

sorry i didnt get on the audio threads the last couple days! first off the jbl speakers should be at an 8ohm impedance and the new radio will run at 4ohm per channel so if you want any decent sound and you are bypassing the jbl amp for the door speakers you will need to change the door speakers also.. if you are bypassing the amp then there is no need for the expensive jbl harness you can just get 12v, ignition and ground at the harness that you unplug from the radio.. if you have any other questions just pm me and i should be able to help..

these are the wires to splice into on the harness behind the radio..
12v- blue with yellow stripe
ignition- gray
ground-brown