2013 Silverado after market stereo options?

I have the non-bose/non-nav factory system. I would like to upgrade at least the speakers, adding a sub, and amps. It would be nice to upgrade the headunit also, but working on chevy units in the past i know it can take alot to retain factory functions. the last chevys i worked on were ~2005 models. In know alot must have changed since then. I really like all the integration of bluetooth, steering controls, and factory satellite radio that come with the newer factory systems. I am looking for the same functionality, but better sound.

So I am looking for input for modules i would need to:

1. just add in amps...been looking at audiocontrol lc7i to get preamp outputs and sub control. but i need to know if the bluetooth etc will still work correctly through the speakers since i would be running a 4ch amp and new speaker wire to the doors.
(this is my most likely option of the 2)

2. if i wanted to upgrade the headunit, what would be needed to retain all the factory integration, ie. sw controls, sat radio, bluetooth, onstar, etc

thanks in advance for the help.

The answer to question 2 is Pac-Audio.com RP5GM31