Need help with a head unit
 

I have an idea of which head unit i want which is the one below but I want to know what i will need to install it. I know i need the 2-din bracket which can be bought through circuit city but i am not sure what else. I also want to keep onstar and the radio controls on the steering wheel how can i do that (i know this has been explained already in other threads but i need a clear answer). And one more question will i be able to somehow incorporate the xm that is used in the stock radio with this radio even though its sirius sat. radio ready.Can the xm that comes in the car be even used in another stereo or is it just incorporated in the stock (basically do i need to by an xm sat adapter and waste more $ :lol: )
Thanks for any advice in advance:twothumbs

IVA-W200
2-DIN DVD/CD/MP3/WMA Receiver/AV Head Unit

http://i133.photobucket.com/albums/q...ink/alpine.jpg


2006 cobalt ss s/c
https://www.cobaltss.net/images/sigs/sc_black.jpg