PAC audio has a steering wheel control device(device, aparatus etc. that can be configured to what ever vehicle and head unit etc,
same company also offers a radio replacement wiring adaptor install kit
i think it has an option to include or it comes with the steering wheel control kit,
Metra also offers the same.
the steering wheel control kit seperatly isnt that expensive, (under 20 on amazon)
the radio wiring harness adaptor is the pricey item, and both PAC and Metra are the same price, which is around $130.00)
isimple makes some adaptors as well.
if asking for H/u suggestions, Personally recommend Kenwood Excelon line.
hope it helps
im in process of shopping around researching etc about what route to go regarding the stereo system ( The LLY has the bose system with the aplillar tweets and the console sub, etc. and if i want to go the replace headunit, route, or do one of these modifications that utilize the XM radIO Input with adding in a bluetooth function and an aux jack etc, and then maybe a bose amp from the denali or escalade swap.