Audio Systems: amp, sub, and components, infinity kappa 60, bose system

Question
I have an 04 350z with the non bose system. I want to install a jl 10w3v3 i believe 4ohm sub and infinity kappa 60.7 cs 6.5 2 ohm components in the doors, and
an amp to power this that can send about 150-200 watts to sub and 50-65 watts to the components. I want to keep my oem headunit, so what all do i
need, and how can i wire the sub? I think that there are wires for a
sub behind drivers seat that i might can tap into. I know that a line
out converter is needed, though i dont know what kind, how many watts? I was also told i could get an amp with speaker level inputs that would not require an loc?
Please go into depth in the answer as far as what i need and how to do
it, i know next to nothing about car audio. Thanks

Answer
By your own admission you know little about installation of the system you are proposing.

I strongly advise you to seek a professional installer to do this job.  The 350z has sophisticated electronics and there is overlap between the entertainment system and the chimes, locks and other features of the car.  The installation you speak of requires a wiring harness and some additional wires to be run through the racer channels.

This, as you have described it, is NOT an amateur job and the cost of hiring an installer will be money well spent.

So, I urge you to go to a good installer and have them work it out and give you advice on the sub power and woofer location.   That will be best and you will thank me for insisting on it!

Cleggsan