what all do I need in order for the double din setup to work with the bose sound system and the steering wheel controls? Also in the future if I want to upgrade the sound system and put a subs and a amp in what would I have to buy a new screen or something?

 

Search is your friend this has been covered a 100 times man. You can get the parts from Grubbs and this will get you started https://g35driver.com/forums/audio-video-electronics/55231-pioneer-avic-d1-avic-z1-double-din-conv-pics.html

 

for the steering wheel controls it depends on the deck you will use PAC SWI-??? depending on the deck.

 

+1 search will be your friend here.

 

Thanks for the search advice. Always helpful