Updating the sound in my truck

Got tired of the shitty Bose in the truck, and have a bunch of speakers sitting in a closet that I've collected over the years. I plan on putting it in when it gets warm for a day or two, but need to know if I need anything else to get this to work because I've never upgraded a Bose system, and have been out of the game for a while. It os an 04 Silverado 2500HD crew cab with Onstar, rear radio controls, and all of that business. I don't listen to rap or anything with boomy bass, and don't want to lose space behind the rear seats, so a bigger sub back there or under the seat is out of the question.

I am planning on this head unit Pioneer 5600, this dash kit Scoshe, this harness PAC RP5-GM11. Is that everything I need to keep the stock functionality like radio controls, onstar, door dingers, and rear controls?

Stuff I have sitting in a closet:
Boston Pro 6.5 components for the front
SR80 5x7s for the rear
Eclipse 4/3/2 highs amp @ 125x4
MTX 250d sub amp
All new 18AWG wiring for speakers, and proper sized wiring for amps

I ordered one of these Tang Band 6.5" sub because I want it to all look stock, with the exception of the radio. I planned on putting that in place of the stock Bose sub that faces the firewall, and wiring it to the MTX amp.


Am I missing anything? Do I need any other wiring shite to keep the radio and controls working like it was stock?